This happens also on another older versions of max ~2012-x only difference which I can see is that the switching between selections looks even slower on 2018 then on 2015 for example. Unfortunately I can't help you. This looks like redrawing GUI problem.
Hey guys, just a little update on this issue. I started having the same sluggish Command Menu all of a sudden on my 3dsmax 2021 and none of the above things helped with it. I'm talking the simplest select deselect is taking 2 - 3 seconds, not to mention switching between the create and modify tabs in the menu. For me, the…