diff --git a/src/Model/APContact.php b/src/Model/APContact.php
index ba2e3c973..841c02890 100644
--- a/src/Model/APContact.php
+++ b/src/Model/APContact.php
@@ -539,6 +539,13 @@ class APContact
 		HTTPSignature::setInboxStatus($url, true, $shared);
 	}
 
+	/**
+	 * Check if the apcontact is a relay account
+	 *
+	 * @param array $apcontact
+	 *
+	 * @return bool 
+	 */
 	public static function isRelay(array $apcontact): bool
 	{
 		if ($apcontact['nick'] != 'relay') {
@@ -549,7 +556,7 @@ class APContact
 			return true;
 		}
 
-		if (in_array($apcontact['type'], ['Group', 'Service']) && ($apcontact['nick'] == 'relay') && is_null($apcontact['outbox'])) {
+		if (in_array($apcontact['type'], ['Group', 'Service']) && is_null($apcontact['outbox'])) {
 			return true;
 		}
 
diff --git a/src/Model/Item.php b/src/Model/Item.php
index 414295356..3ae23412e 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -683,19 +683,19 @@ class Item
 			'uri-id', 'parent-uri-id',
 			'allow_cid', 'allow_gid', 'deny_cid', 'deny_gid',
 			'wall', 'private', 'origin', 'author-id'];
-		$condition = ['uri-id' => $item['thr-parent-id'], 'uid' => $item['uid']];
+		$condition = ['uri-id' => [$item['thr-parent-id'], $item['parent-uri-id']], 'uid' => $item['uid']];
 		$params = ['order' => ['id' => false]];
 		$parent = Post::selectFirst($fields, $condition, $params);
 
-		if (!DBA::isResult($parent) && ($item['thr-parent-id'] != $item['parent-uri-id'])) {
-			$condition = ['uri-id' => $item['parent-uri-id'], 'uid' => $item['uid']];
-			$parent = Post::selectFirst($fields, $condition, $params);
-		}
-
-		if (!DBA::isResult($parent) && $item['origin']) {
+		if (!DBA::isResult($parent) && Post::exists(['uri-id' => [$item['thr-parent-id'], $item['parent-uri-id']], 'uid' => 0])) {
 			$stored = Item::storeForUserByUriId($item['thr-parent-id'], $item['uid']);
-			Logger::info('Stored thread parent item for user', ['uri-id' => $item['thr-parent-id'], 'uid' => $item['uid'], 'stored' => $stored]);
-			$parent = Post::selectFirst($fields, $condition, $params);
+			if (!$stored && ($item['thr-parent-id'] != $item['parent-uri-id'])) {
+				$stored = Item::storeForUserByUriId($item['parent-uri-id'], $item['uid']);
+			}
+			if ($stored) {
+				Logger::info('Stored thread parent item for user', ['uri-id' => $item['thr-parent-id'], 'uid' => $item['uid'], 'stored' => $stored]);
+				$parent = Post::selectFirst($fields, $condition, $params);
+			}
 		}
 
 		if (!DBA::isResult($parent)) {
@@ -908,7 +908,7 @@ class Item
 		$item['contact-id'] = self::contactId($item);
 
 		if (!empty($item['direction']) && in_array($item['direction'], [Conversation::PUSH, Conversation::RELAY]) &&
-			empty($item['origin']) &&self::isTooOld($item)) {
+			empty($item['origin']) && self::isTooOld($item)) {
 			Logger::info('Item is too old', ['item' => $item]);
 			return 0;
 		}
diff --git a/src/Protocol/ActivityPub/Processor.php b/src/Protocol/ActivityPub/Processor.php
index 28192d35b..9c7cfef77 100644
--- a/src/Protocol/ActivityPub/Processor.php
+++ b/src/Protocol/ActivityPub/Processor.php
@@ -299,7 +299,7 @@ class Processor
 		if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 			$recursion_depth = $activity['recursion-depth'] ?? 0;
 			Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
-			if ($recursion_depth < 10000) {
+			if ($recursion_depth < 10) {
 				$result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 				$fetch_by_worker = empty($result);
 			} else {
diff --git a/src/Protocol/ActivityPub/Receiver.php b/src/Protocol/ActivityPub/Receiver.php
index 1cbd5c9e3..92ed31922 100644
--- a/src/Protocol/ActivityPub/Receiver.php
+++ b/src/Protocol/ActivityPub/Receiver.php
@@ -437,17 +437,18 @@ class Receiver
 		$object_data['receiver'] = array_replace($object_data['receiver'] ?? [], $receivers);
 		$object_data['reception_type'] = array_replace($object_data['reception_type'] ?? [], $reception_types);
 
-		$author = $object_data['author'] ?? $actor;
-		if (!empty($author) && !empty($object_data['id'])) {
-			$author_host = parse_url($author, PHP_URL_HOST);
-			$id_host = parse_url($object_data['id'], PHP_URL_HOST);
-			if ($author_host == $id_host) {
-				Logger::info('Valid hosts', ['type' => $type, 'host' => $id_host]);
-			} else {
-				Logger::notice('Differing hosts on author and id', ['type' => $type, 'author' => $author_host, 'id' => $id_host]);
-				$trust_source = false;
-			}
-		}
+//		This check here interferes with Hubzilla posts where the author host differs from the host the post was created
+//		$author = $object_data['author'] ?? $actor;
+//		if (!empty($author) && !empty($object_data['id'])) {
+//			$author_host = parse_url($author, PHP_URL_HOST);
+//			$id_host = parse_url($object_data['id'], PHP_URL_HOST);
+//			if ($author_host == $id_host) {
+//				Logger::info('Valid hosts', ['type' => $type, 'host' => $id_host]);
+//			} else {
+//				Logger::notice('Differing hosts on author and id', ['type' => $type, 'author' => $author_host, 'id' => $id_host]);
+//				$trust_source = false;
+//			}
+//		}
 
 		Logger::info('Processing ' . $object_data['type'] . ' ' . $object_data['object_type'] . ' ' . $object_data['id']);
 
@@ -580,7 +581,16 @@ class Receiver
 		}
 	}
 
-	public static function routeActivities($object_data, $type, $push)
+	/**
+	 * Route activities
+	 *
+	 * @param array   $object_data
+	 * @param string  $type
+	 * @param boolean $push
+	 *
+	 * @return boolean Could the activity be routed?
+	 */
+	public static function routeActivities(array $object_data, string $type, bool $push): bool
 	{
 		$activity = $object_data['object_activity']	?? [];
 
@@ -627,7 +637,7 @@ class Receiver
 
 					$item = ActivityPub\Processor::createItem($object_data);
 					if (empty($item)) {
-						return;
+						return false;
 					}
 
 					$item['post-reason'] = Item::PR_ANNOUNCEMENT;
diff --git a/src/Util/JsonLD.php b/src/Util/JsonLD.php
index 1200a9cbe..947274134 100644
--- a/src/Util/JsonLD.php
+++ b/src/Util/JsonLD.php
@@ -177,6 +177,13 @@ class JsonLD
 			}
 		}
 
+		// Bookwyrm transmits "id" fields with "null", which isn't allowed.
+		array_walk_recursive($json, function (&$value, $key) {
+			if ($key == 'id' && is_null($value)) {
+				$value = '';
+			}
+		});
+
 		$jsonobj = json_decode(json_encode($json, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE));
 
 		try {