I suddenly can't do anything on my fb.
All actions fail to post.
Am I shadowbanned?
I dont think so. When shadow banned, you can do actions, but your actions notifications will not be sent to others. Maybe your have been being BANNED, or check your DNS, network & etc.
No, it's not just me. I'm seeing a bunch of people posting about fb being wonky and not being able to use things like commenting. I couldn't comment or like those posts, either.