If you’re on a user’s page (like here I am on @scientiffic) and you bring up a user card and hover/click the name:
The link is wrong, because it’s relative to current page.
So where we have
/@scientiffic/@AngeloStavrow it should just be
This happens reliably IF the URL bar has a terminating slash OR if you’re an a user’s playlist page.
If there’s no terminating slash, usually the correct thing happens. But it’s possible to click around and get into the bug state without changing the URL manually.