Hello,
since I posted the following bug, epic tried to fix it, but now there a more complex bug in UE4.22.1 that depends to the old bug.
My old bug report
The grass is popping around when you are using dithered lod transition and having a difference in the min and max scale value of the landscape grass type.
Check out the video:
If the min and max value of the Landscape Grass Type is the same, it has no effect.
If the dithered lod transition is disabled, it works, but when it is enabled, the grass is popping
Here is a small example project: