[bug] Posts in incorrect communities (0.17.3 - 0.18.0)

On lemmy.world (where I'm mostly at) I see local communities getting posts in threads that are clearly for another thread. World still runs on 0.17.3, as the captcha is disabled in 0.18.0 and 0.18.1-rc1 gave issues.

Is this a known issue with federation between versions or limited to the old version?