Mouse response, level rotates. I tried disable my inner GPU (working on laptop), it doesn’t help. My system gpu is 1050ti, so i dont think the problem is in software.
I once tried opening a 4.20 tutorial in 4.21, it started converting it and my CPU load increased to 100 % and then my system crashed completely. If your internet is fine I suggest you downloaded the 4.21-version tutorial project.