UPDATE: Stopping and reopening the app fixes this. It needs to actually stop though, you can’t just switch apps and reopen. Either wait for it to close on its own or force stop. I did not try the main menu method as suggested, though. It may be easier.
It’s a known bug on mobile. You need to return to the main menu, then you can continue your run.
You can’t really deselect it on mobile since you’re not supposed to be able to select them like this in the first place, afaik.