Every since the new One UI software was added, when YouTube goes into the picture-in-picture, sometimes it will glitch and freeze the screen until I somehow get YouTube app back open. Sometimes the player gets stuck at the bottom of the screen and goes below the screen and even if I try to move it it disappears and glitches but it still plays.
Once I restart my phone it fixes the bug, but somehow it bugs back. If I don't have a text box it makes it really difficult to get the player back up. The minor screen wiggling appears a lot stronger a lot of times