It might be related to this bug: https://github.com/LemmyNet/lemmy/issues/4003
It doesn’t seem to block all special characters though. I was able to put square brackets in the title.
EDIT: for some reason it allowed single quotes when editing my post. Maybe it was just the ‘&’ that was causing issues.
EDIT2: ‘&’ doesn’t seem to cause issues in posts either. It may just be effecting the bio and nothing else.
EDIT3: I’m getting an error that says: SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data when trying to upload an avatar. I’m removing [solved] from the title for now. I’m also going to submit an issue on github later.
EDIT4: fixed some formatting issues
EDIT5: putting ‘&’ in a code block causes issues. It’s because of this bug: https://github.com/LemmyNet/lemmy/issues/3754
I figured it out. It won’t save any of my settings if I use special characters in my bio. It may be related to this issue: https://github.com/LemmyNet/lemmy/issues/4003