Non-existing files stuck on "Out of Sync Items"

They’re still send-/receive-only, I haven’t changed that. It’s actually shown on the first screenshot. Maybe you got confused with the 2nd screenshot - that’s just the sever details, no folder details (to illustrate each machine’s state and how they see each other).

This did the trick! Thanks a lot for the support and patience, it’s working great now.

I wish there’s a way to tag your post as the solution. So that people with similar issues can quickly find it.