Randomly appearing black spot near battery indicator

I'm not sure if this is a common issue with the S21, but it's the first time I have had an issue with a smartphone. This is the second time it's happened in thr past week or so. Rebooting the phone seems to fix the problem.

https://i.imgur.com/bySrWnj.jpeg

The black spot isn't present in screenshots, so it must be hardware level. Dead AMOLED or something else?