Can't stream live on YouTube?

I'm a YouTuber on PC and I often do live streams.
since about 2 weeks I can no longer do livestreams on youtube.

Whenever I press "Start Livestream" on OBS, I'm "Live"

but when i watch youtube i'm not live

I don't think it's OBS because I can stream on twitch

Have you ever checked whether your stream key is still correct?

Yes I have