SOLUTION FOUND!
Hi smarter people than me...
I am on latest max, 2020.1. Using a 72Core machine with tons of ram and an RTX5000 and a P5000. The monitor is hooked up to the RTX. All day I've been troubleshooting an issue and think I am finally onto the problem.
Basically, I have a heavyish scene with lots of sub objects, ~5M polys. When I stop moving the viewport it locks for a millisecond and then objects disappear. It seems to affect the shaded view only, wire is fine. It occurs in high quality, clay, or standard mode. I've tried updating windows, the nvidia drivers (using clean install option), checking scene bounds, checking pivots, and isolated vertices. I tried rolling back to older drivers. I tried importing my objects into a fresh max. I tried disabling the view cube too. All according to some previous posts.
No Luck. Things still disappear and viewport doesn't refresh correctly.
Then it occured to me maybe it isn't the viewport/driver really, but something in the viewport that is miscalculating and glitching it out. So I wiped the materials on all my objects and it was perfect. So I narrowed it down to be a material issue... but what?!
So then, I cloned my material, a multi-sub with 7 parts, and went at them a part at a time. Turns out, it is the BUMP channel. I have a removed that and all is fine. I had a vrayComposite with both Edges and a standard procedural Noise, in it. So i removed that and tried them one at a time to see. Turns out the procedural noise in the bump channel was the culprit. Doesn't seem to do it with checker or bitmap. So I switched my procedural to a map and used Triplanar and it fixes it completely.
So what appeared to be a bad driver issue, turns out to be some odd bug linked to a procedural mapped to a bump channel.
Pretty frickin strange. Someone needs to see if they can create a replicable scene and try this solution. and someone has to figure out if it is NVIDIA or AUTODESK that has the bug.