diff --git a/database.sql b/database.sql
index 7663b7159..6126e58a8 100644
--- a/database.sql
+++ b/database.sql
@@ -1,6 +1,6 @@
 -- ------------------------------------------
 -- Friendica 2022.09-dev (Giant Rhubarb)
--- DB_UPDATE_VERSION 1477
+-- DB_UPDATE_VERSION 1478
 -- ------------------------------------------
 
 
@@ -1716,6 +1716,24 @@ CREATE TABLE IF NOT EXISTS `user-contact` (
 	FOREIGN KEY (`uri-id`) REFERENCES `item-uri` (`id`) ON UPDATE RESTRICT ON DELETE CASCADE
 ) DEFAULT COLLATE utf8mb4_general_ci COMMENT='User specific public contact data';
 
+--
+-- TABLE arrived-activity
+--
+CREATE TABLE IF NOT EXISTS `arrived-activity` (
+	`object-id` varbinary(255) NOT NULL COMMENT 'object id of the incoming activity',
+	`received` datetime COMMENT 'Receiving date',
+	 PRIMARY KEY(`object-id`)
+) ENGINE=MEMORY DEFAULT COLLATE utf8mb4_general_ci COMMENT='Id of arrived activities';
+
+--
+-- TABLE processed-activity
+--
+CREATE TABLE IF NOT EXISTS `processed-activity` (
+	`object-id` varbinary(255) NOT NULL COMMENT 'object id of the incoming activity',
+	`received` datetime COMMENT 'Receiving date',
+	 PRIMARY KEY(`object-id`)
+) ENGINE=MEMORY DEFAULT COLLATE utf8mb4_general_ci COMMENT='Id of processed activities';
+
 --
 -- TABLE worker-ipc
 --
diff --git a/doc/database.md b/doc/database.md
index 2bd2fa5f4..fe505ce18 100644
--- a/doc/database.md
+++ b/doc/database.md
@@ -13,6 +13,7 @@ Database Tables
 | [application](help/database/db_application) | OAuth application |
 | [application-marker](help/database/db_application-marker) | Timeline marker |
 | [application-token](help/database/db_application-token) | OAuth user token |
+| [arrived-activity](help/database/db_arrived-activity) | Id of arrived activities |
 | [attach](help/database/db_attach) | file attachments |
 | [cache](help/database/db_cache) | Stores temporary data |
 | [config](help/database/db_config) | main configuration storage |
@@ -67,6 +68,7 @@ Database Tables
 | [post-user](help/database/db_post-user) | User specific post data |
 | [post-user-notification](help/database/db_post-user-notification) | User post notifications |
 | [process](help/database/db_process) | Currently running system processes |
+| [processed-activity](help/database/db_processed-activity) | Id of processed activities |
 | [profile](help/database/db_profile) | user profiles data |
 | [profile_field](help/database/db_profile_field) | Custom profile fields |
 | [push_subscriber](help/database/db_push_subscriber) | Used for OStatus: Contains feed subscribers |
diff --git a/doc/database/db_arrived-activity.md b/doc/database/db_arrived-activity.md
new file mode 100644
index 000000000..1587c6e31
--- /dev/null
+++ b/doc/database/db_arrived-activity.md
@@ -0,0 +1,22 @@
+Table arrived-activity
+===========
+
+Id of arrived activities
+
+Fields
+------
+
+| Field     | Description                        | Type           | Null | Key | Default | Extra |
+| --------- | ---------------------------------- | -------------- | ---- | --- | ------- | ----- |
+| object-id | object id of the incoming activity | varbinary(255) | NO   | PRI | NULL    |       |
+| received  | Receiving date                     | datetime       | YES  |     | NULL    |       |
+
+Indexes
+------------
+
+| Name    | Fields    |
+| ------- | --------- |
+| PRIMARY | object-id |
+
+
+Return to [database documentation](help/database)
diff --git a/doc/database/db_processed-activity.md b/doc/database/db_processed-activity.md
new file mode 100644
index 000000000..618b46f97
--- /dev/null
+++ b/doc/database/db_processed-activity.md
@@ -0,0 +1,22 @@
+Table processed-activity
+===========
+
+Id of processed activities
+
+Fields
+------
+
+| Field     | Description                        | Type           | Null | Key | Default | Extra |
+| --------- | ---------------------------------- | -------------- | ---- | --- | ------- | ----- |
+| object-id | object id of the incoming activity | varbinary(255) | NO   | PRI | NULL    |       |
+| received  | Receiving date                     | datetime       | YES  |     | NULL    |       |
+
+Indexes
+------------
+
+| Name    | Fields    |
+| ------- | --------- |
+| PRIMARY | object-id |
+
+
+Return to [database documentation](help/database)
diff --git a/src/Module/Debug/ActivityPubConversion.php b/src/Module/Debug/ActivityPubConversion.php
index ec7fee3f4..8593de81c 100644
--- a/src/Module/Debug/ActivityPubConversion.php
+++ b/src/Module/Debug/ActivityPubConversion.php
@@ -22,15 +22,10 @@
 namespace Friendica\Module\Debug;
 
 use Friendica\BaseModule;
-use Friendica\Content\Text;
-use Friendica\Core\Logger;
 use Friendica\Core\Renderer;
 use Friendica\DI;
-use Friendica\Model\Item;
-use Friendica\Model\Tag;
 use Friendica\Protocol\ActivityPub;
 use Friendica\Util\JsonLD;
-use Friendica\Util\XML;
 
 class ActivityPubConversion extends BaseModule
 {
@@ -123,7 +118,7 @@ class ActivityPubConversion extends BaseModule
 					'content' => visible_whitespace(var_export($object_data, true))
 				];
 
-				$item = ActivityPub\Processor::createItem($object_data);
+				$item = ActivityPub\Processor::createItem($object_data, true);
 
 				$results[] = [
 					'title'   => DI::l10n()->t('Result Item'),
diff --git a/src/Protocol/ActivityPub/Processor.php b/src/Protocol/ActivityPub/Processor.php
index d345ba78c..a8d51da43 100644
--- a/src/Protocol/ActivityPub/Processor.php
+++ b/src/Protocol/ActivityPub/Processor.php
@@ -60,33 +60,29 @@ class Processor
 	const CACHEKEY_FETCH_ACTIVITY = 'processor:fetchMissingActivity:';
 	const CACHEKEY_JUST_FETCHED   = 'processor:isJustFetched:';
 
-	static $processed = [];
-
 	/**
-	 * Add an activity id to the list of processed ids
+	 * Add an object id to the list of processed ids
 	 *
 	 * @param string $id
 	 *
 	 * @return void
 	 */
-	public static function addActivityId(string $id)
+	private static function addActivityId(string $id)
 	{
-		self::$processed[] = $id;
-		if (count(self::$processed) > 100) {
-			self::$processed = array_slice(self::$processed, 1);
-		}
+		DBA::delete('processed-activity', ["`received` < ?", DateTimeFormat::utc('now - 5 minutes')]);
+		DBA::insert('processed-activity', ['object-id' => $id, 'received' => DateTimeFormat::utcNow()]);
 	}
 
 	/**
-	 * Checks if the given has just been processed
+	 * Checks if the given object id has just been processed
 	 *
 	 * @param string $id
 	 *
 	 * @return boolean
 	 */
-	public static function isProcessed(string $id): bool
+	private static function isProcessed(string $id): bool
 	{
-		return in_array($id, self::$processed);
+		return DBA::exists('processed-activity', ['object-id' => $id]);
 	}
 
 	/**
@@ -233,7 +229,7 @@ class Processor
 		$item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
 		if (!DBA::isResult($item)) {
 			Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
-			$item = self::createItem($activity);
+			$item = self::createItem($activity, false);
 			if (empty($item)) {
 				return;
 			}
@@ -303,7 +299,7 @@ class Processor
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function createItem(array $activity, bool $fetch_parents = true): array
+	public static function createItem(array $activity, bool $fetch_parents): array
 	{
 		if (self::isProcessed($activity['id'])) {
 			Logger::info('Id is already processed', ['id' => $activity['id']]);
@@ -324,10 +320,10 @@ class Processor
 			$item['object-type'] = Activity\ObjectType::COMMENT;
 		}
 
-		if (!empty($activity['context'])) {
-			$item['conversation'] = $activity['context'];
-		} elseif (!empty($activity['conversation'])) {
+		if (!empty($activity['conversation'])) {
 			$item['conversation'] = $activity['conversation'];
+		} elseif (!empty($activity['context'])) {
+			$item['conversation'] = $activity['context'];
 		}
 
 		if (!empty($item['conversation'])) {
@@ -340,6 +336,7 @@ class Processor
 			$conversation = [];
 		}
 
+		Logger::debug('Create Item', ['id' => $activity['id'], 'conversation' => $item['conversation'] ?? '']);
 		if (empty($activity['author']) && empty($activity['actor'])) {
 			Logger::notice('Missing author and actor. We quit here.', ['activity' => $activity]);
 			return [];
@@ -490,11 +487,6 @@ class Processor
 	 */
 	private static function fetchParent(array $activity): string
 	{
-		if (self::hasJustBeenFetched($activity['reply-to-id'])) {
-			Logger::notice('We just have tried to fetch this activity. We don\'t try it again.', ['parent' => $activity['reply-to-id']]);
-			return '';
-		} 
-
 		$recursion_depth = $activity['recursion-depth'] ?? 0;
 
 		if ($recursion_depth < DI::config()->get('system', 'max_recursion_depth')) {
@@ -552,23 +544,6 @@ class Processor
 		return '';
 	}
 
-	/**
-	 * Check if a given activity has recently been fetched
-	 *
-	 * @param string $url
-	 * @return boolean
-	 */
-	private static function hasJustBeenFetched(string $url): bool
-	{
-		$cachekey = self::CACHEKEY_JUST_FETCHED . $url;
-		$time = DI::cache()->get($cachekey);
-		if (is_null($time)) {
-			DI::cache()->set($cachekey, time(), Duration::FIVE_MINUTES);
-			return false;
-		}
-		return ($time + 300) > time();
-	}
-
 	/**
 	 * Check if a given activity is no longer available
 	 *
@@ -656,7 +631,7 @@ class Processor
 	public static function createActivity(array $activity, string $verb)
 	{
 		$activity['reply-to-id'] = $activity['object_id'];
-		$item = self::createItem($activity);
+		$item = self::createItem($activity, false);
 		if (empty($item)) {
 			return;
 		}
@@ -1419,7 +1394,7 @@ class Processor
 
 		$ldactivity = JsonLD::compact($activity);
 
-		$ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 1;
+		$ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 0;
 
 		if (!empty($relay_actor)) {
 			$ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
diff --git a/src/Protocol/ActivityPub/Receiver.php b/src/Protocol/ActivityPub/Receiver.php
index 1f7946af2..e8267b0ea 100644
--- a/src/Protocol/ActivityPub/Receiver.php
+++ b/src/Protocol/ActivityPub/Receiver.php
@@ -586,11 +586,19 @@ class Receiver
 			$object_data['object_activity']	= $activity;
 		}
 
-		if (($type == 'as:Create') && Queue::exists($object_data['object_id'], $type)) {
-			Logger::info('The activity is already added.', ['id' => $object_data['object_id']]);
-			return true;
-		}
+		if (($type == 'as:Create') && $trust_source) {
+			if (self::hasArrived($object_data['object_id'])) {
+				Logger::info('The activity already arrived.', ['id' => $object_data['object_id']]);
+				return true;
+			}
+			self::addArrivedId($object_data['object_id']);
 
+			if (Queue::exists($object_data['object_id'], $type)) {
+				Logger::info('The activity is already added.', ['id' => $object_data['object_id']]);
+				return true;
+			}
+		}
+	
 		if (DI::config()->get('system', 'decoupled_receiver') && ($trust_source || DI::config()->get('debug', 'ap_inbox_store_untrusted'))) {
 			$object_data = Queue::add($object_data, $type, $uid, $http_signer, $push, $trust_source);
 		}
@@ -1883,4 +1891,29 @@ class Receiver
 
 		return $object_data;
 	}
+
+	/**
+	 * Add an object id to the list of arrived activities
+	 *
+	 * @param string $id
+	 *
+	 * @return void
+	 */
+	private static function addArrivedId(string $id)
+	{
+		DBA::delete('arrived-activity', ["`received` < ?", DateTimeFormat::utc('now - 5 minutes')]);
+		DBA::insert('arrived-activity', ['object-id' => $id, 'received' => DateTimeFormat::utcNow()]);
+	}
+
+	/**
+	 * Checks if the given object already arrived before
+	 *
+	 * @param string $id
+	 *
+	 * @return boolean
+	 */
+	private static function hasArrived(string $id): bool
+	{
+		return DBA::exists('arrived-activity', ['object-id' => $id]);
+	}
 }
diff --git a/static/dbstructure.config.php b/static/dbstructure.config.php
index f72ec0802..df5115dcb 100644
--- a/static/dbstructure.config.php
+++ b/static/dbstructure.config.php
@@ -55,7 +55,7 @@
 use Friendica\Database\DBA;
 
 if (!defined('DB_UPDATE_VERSION')) {
-	define('DB_UPDATE_VERSION', 1477);
+	define('DB_UPDATE_VERSION', 1478);
 }
 
 return [
@@ -1723,6 +1723,28 @@ return [
 			"uri-id_uid" => ["UNIQUE", "uri-id", "uid"],
 		]
 	],
+	"arrived-activity" => [
+		"comment" => "Id of arrived activities",
+		"fields" => [
+			"object-id" => ["type" => "varbinary(255)", "not null" => "1", "primary" => "1", "comment" => "object id of the incoming activity"],
+			"received" => ["type" => "datetime", "comment" => "Receiving date"],
+		],
+		"indexes" => [
+			"PRIMARY" => ["object-id"],
+		],
+		"engine" => "MEMORY",
+	],
+	"processed-activity" => [
+		"comment" => "Id of processed activities",
+		"fields" => [
+			"object-id" => ["type" => "varbinary(255)", "not null" => "1", "primary" => "1", "comment" => "object id of the incoming activity"],
+			"received" => ["type" => "datetime", "comment" => "Receiving date"],
+		],
+		"indexes" => [
+			"PRIMARY" => ["object-id"],
+		],
+		"engine" => "MEMORY",
+	],
 	"worker-ipc" => [
 		"comment" => "Inter process communication between the frontend and the worker",
 		"fields" => [