UPDATE
I upgraded to the last version.
I replaced my DELL Monitor video cable from HDMI to DisplayProt, so that I am able to use 60Hz for both of my two monitor.
Condition is much better that past, but still has some problem.
In Windows Edge, it is not PROBLEM for watch two 4K video! NOT PROBLEM!
In Google Chrome, it is much much better at FULL SCREEN when U DONT MOVE YOUR MOUSE! SO WEIRD!
It 100% happens at moving mouse, which screen you move, which screen will shows up the mess!
It will happen when video is loading not long enough (my network is 1000M)
My guess is
1. the mess prefer shows up when high CPU use,
2. software doesn't optimize enough.
3. two Monitors have different reflash frequency will cause the mess more heavier.