Cannot link forums acc (but also can?)

Title. I do /forum in-game and follow the link. Takes me here:



That's odd, to what account could it already be linked?



NotHealthy, the account to which I'm trying to link it, of course.



...the account that's not linked to the forums.

Any help on fixing is appreciated, just want the white name :V

 

I also have this
I just live with it