The issue is not overall game breaking - but it certainly impacts that character! Orlyia (not a GM) did look at your account for you and on Blizzard’s end there is nothing displaying as an alpha numeric sequence.
It was suggested that maybe Maint would refresh it, or that you could try a full UI reset in case the char data client side was corrupted. This is your last reply there. Did you actually do the UI reset? The is usually the first step in troubleshooting things that display wrong, like names. If you have not confirmed that you did that, they likely will tell you to do it again. Heh.
Here is the link for the procedure. It is more than just turning off addons. https://us.battle.net/support/en/article/7549
If you want, I can bump the thread for you. As the OP I don’t think you can double reply to your own thread.