Strange. I have exactly the same problem, but when I turned off “disable automatic hiding of the taskbar” nothing changed.
I have a GTX 1650 Super video card.
I did a little research on the problem itself to understand how it works. UE optionally reduces the frame rate itself when I aim at something. For example, if I have a limit of 60 fps, then when hovering it will reduce to 30/20/15. When I set it to 70, it reduces to 35/22/16.
Has anyone found another solution to this problem?