Discord icon won't disappear from Mac

When I start up Discord on my MacBook Pro a Discord Icon appears and even when I quite Discord it remains and cannot be removed without restarting the laptop. It appears at the top of the screen, in the middle and down just a little from the top. I have installed Big Sur version 11.0.1. I think this problem preceded this installation by a few weeks, but can't be absolutely sure. I have tried deleting any Discord related programmes shown in Activity Monitor. Any solutions?