Update Helpers.php

app/Util/ActivityPub/Helpers.php

@@ -689,13 +689,14 @@ class Helpers
             return $option['replies']['totalItems'] ?? 0;
         })->toArray();
 
+        $defaultCaption = config_cache('database.default') === 'mysql' ? null : "";
         $status = new Status;
         $status->profile_id = $profile->id;
         $status->url = isset($res['url']) ? $res['url'] : $url;
         $status->uri = isset($res['url']) ? $res['url'] : $url;
         $status->object_url = $id;
-        $status->caption = strip_tags(Purify::clean($res['content'])) ?? "";
-        $status->rendered = "";
+        $status->caption = strip_tags(Purify::clean($res['content'])) ?? $defaultCaption;
+        $status->rendered = $defaultCaption;
         $status->created_at = Carbon::parse($ts)->tz('UTC');
         $status->in_reply_to_id = null;
         $status->local = false;