cannot post articles that have punctuation like ‘N?o’. Just breaks entire post

Hello ??

Whenever I try to post something with punctuation, it can be on title or inside the post body, it just breaks my entire post.

If I try to post this:

Eu sou n?o além

The post will became : Eu sou n

That started to happen with no reason, updated tp 2.7 and the issue still there.
Tried changing encoding on wp-config with no sucess on this.
What could be?
Please help. Thanks!!