Ue4 create a few strange after Images when you move, but only on masked surfaces. This problem is fixed when you disable TemporalAA. I’ve also seen this problem at Conan Exiles and Ark (two new Ue4 games on steam).
disable SSR and motion blur make no difference. and the game works whit 60 fps
The material in the background is a simple mask material without extra settings, It only has a noise texture for “Opacity Mask”
And the same effect I get at grass whit ditherTemporalAA