Cannot Play Matchmaking

I recently changed my Xbox gamertag from Ockmeck to Ω Ockmeck. After doing so, I lost access to all of my Steam friends and even the recent players, and they cannot add me as a friend, and I cannot add them as a friend. Additionally, once anyone send a group invite, I can accept it, but nothing happens.

Additionally I’ve tried to queue matchmaking solo, but that doesn’t work.

I’ve tried to revert my gamertag assuming the funky Ω symbol was simply creating an issue, but whatever issue that may have causes now persists. I do see my name flicker between Ockmeck and Ω Ockmeck.

Attached you’ll find an image with the error message when trying to add a friend.

Error when trying to add former steam friend