Did I do something wrong? ):

So I've been talking to this person for over a year now on discord (we got extremely close). We did have our ups and downs but after a little accident we had in our friendship, we gave each other this huge apology and been great since (this was almost a month ago). So after work was over last night, I replied back to my friend's message and we had this tiny conversation. After a few replies, I didn't touch my phone for the rest of the night until I woke up this morning. When I go to reply back to his message, I get that message on discord that says "you can't message the person because you don't share a server with them, haven't accepted a friend request, or you've been blocked." I know at that point I've been blocked because we were both on each other's friends list (we were in the same server but he left that server). Like what did I do wrong? He didn't say anything about why he blocked me, and I know it's not because of what happened a month ago. Is it because I didn't pick up my phone the other night to reply back to his text? ._.