Real Name Shown In BattleTag Group Chat

So a few nights ago, someone whom I am in a group chat with was able to see my real name displayed in our chat.

A few facts I’d like to note about this:
-The group is purely a battletag chat group, I have no one in that chat on my real ID
-I did not have the person who was able to see my name added on my friends list at all
-I also had someone else whom is in that chat group check if they could see my real name by temporarily removing them and they couldn’t

I am making this post because this is a MAJOR privacy concern for me. I do NOT want people whom I don’t even have added on real ID to be able to see my real name. This bug makes it almost impossible to keep my private information private.