Temporal-blurring-AA causes ghost effect in main character while moving it. Tested in UHD and 4K.
Good for static images but nothing to do with fast moving scenes.
The solutions aported by epic staff are barely bad:
1)Turn off Temporal-AA
https://answers.unrealengine.com/questions/378696/ghost-effect-while-moving.html
2)Add some sharpness to it
https://answers.unrealengine.com/questions/219715/character-ghosting.html
3)Try FXAA (poor performance and aliasing)
4)Disable Motion-Blur (…but its not related to motion blur)
https://answers.unrealengine.com/questions/30203/strange-ghosting-with-water-decal.html
5)Screen Space Reflections = 0
https://answers.unrealengine.com/questions/157542/heavy-ghosting-with-temporal-antialiasing.html
https://answers.unrealengine.com/questions/394668/3d-hud-rendering-weird-when-character-moves-even-w.html
6)Without response
https://answers.unrealengine.com/questions/395268/texture-flicker-noise-grainy-problem.html
This happens when characters moves in front of displacement or decals textures, and also foliage grass .
https://answers.unrealengine.com/questions/388289/landscape-grass-causes-ghosting.html
Both FXAA an None causes extrange moire-flicker-noise in some textures when moving camera.
Started .ueproject as game with same problems.