I can't play because the game doesn't recognize my account name

My account name Csbears is literally the name of my online presence for like 25 years now and I have had this account since the Alpha version of Minecraft so I know for sure nobody else has taken my name.  When I jump through all the hoops to get my Minecraft account back after all these years (merging with Mojang and all) I can't play the damn game because the launcher doesn't recognize my already logged in name.   I have tried turning off my antivirus and closing / restarting the app and launcher with no success.