Let's hope so!

@flohack@forums.ubports.com subscribing to the category means new topics will be delivered to the follower.

The manual search is just for manually backfilling posts.

@flohack@forums.ubports.com from Mastodon you can manually "pull in" posts by searching for the post URL (not the topic)

Paging @flohack@forums.ubports.com ... come in @flohack@forums.ubports.com

@Flohack might be the view users privilege needs to be on otherwise other services can't resolve the authoring user and drop the activity...

I wasn't able to mention your account on the UBports forum. So that's why I think the view users privilege might be the issue.

@Flohack hi! Sounds like the forum is an upgrade and not a new installation, so activitypub is probably not enabled by default.

It does sound like you figured that out. So can you please send me a screenshot of the privileges page for that category?

Also perhaps you need to grant the view users privilege in global privs.