There's a visual bug on oneui4 that I have only just picked up what causes it, and it may have been on older versions as well and I just didn't notice it.
When exiting an app, and then immediately clicking somewhere else on the screen while the animation is playing e.g. clicking on a folder, a weird effect happens when the app pops up again for a few frames
Additionally, another one I have noticed is where the continuing button from my tab s7 covers up the search feature, so I can't even search anything. This does not seem like a deliberate placement. Also it often isn't visible at all, so it takes me to an app instead of search.
Try wiping the cache partition on the phone and that should resolve the issue. To do this, just search 'how to wipe cache partition S21' and you should find what you are looking for 🙂. Hope this helps! 😎
Hmm. Another problem. I tried to go to recovery mode to wipe the cache but fir some reason I couldn't access it. I haven't had any issues in the past, but nothing would work. I tried taking off my case, pressing the up key before the power key and vice versa, releasing early, not releasing at all, nothing. All it did was boot me into the phone normally. I will investigate this somewhat important issue.