How to fix username glitch?

So basically I made a new acc and I can’t use the username I wanted because of an error. It’s not in use because there was a checkmark when I typed it in, but then then I got an error when I pressed the save button so now it’s acting like the name is in use when it’s in fact NOT. I highly doubt somebody would’ve took the user in the 10 seconds I retyped it so is there any way to still use it? 😭😭 (Btw it’s also not due to the 30 day limit because this is the first time changing it)