I think my friend accidentally blocked me

I don't know this person in real life, or it would be easy to sort out, but we play each other constantly on here. For the last few games, he continues to post in the chat, but I'm unable to. On the app it just displays a red error symbol when I try to write something, and on the website it says "Chat Disabled." I've tried sending him messages, but get no response.

I don't think he's blocked me on purpose, since we're still playing games, and he still posts in the chat. He just must think I'm a jerk for not replying in a couple weeks.

Is there any way I can alert him?

Can you chat in other games without issue? 

One way to verify if you are blocked is to look at their profile on the web and see if you can post a note.

Yeah, I can chat in other games no problem.

I posted a note (it seems like I was able to), will see if that works.