TikTok displaying a legal name it should not have access to? Anyone have this issue?

Hi, as the title states, for some reason when I go to switch account, instead of saying my username when I'm logged in my main account like usual, now it says my EX full government name (literally first, middle and last name). I'm extremely confused and frankly have no idea how this could happen. This is even more shocking since I changed my name YEARS ago, around 2018-19, and have no clue why it even comes up? I cannot find ANYTHING in the settings to change this and its kinda scary. I've never connected my TikTok account to any other social media, and even still all of it has been updated since (or didnt exist under that name), again from the years stated. ALSO, I never used this name when I signed up for TikTok????

It doesn't show up publicly, thankfully, but it's still very weird that it shows up when I try to switch account.

Where did they get it from? Has anyone else experienced this?