@julialuna I wonder why the region locks are being enforced on you to send a toot (#ActivityPub post). It's best to contact the administrator of the instance you have account on (chaos.social) so that they can see what is up.
I could perhaps envision someone doing this to try to prevent content not suitable for family or for work (#NSFW), but since I don't know the full context, I can't advise other thing. It might also be an error.