Did you try rebuilding lights?
If that didn't work... try this little trick: On the engine source code, go to Go to Engine/Shaders/PostProcessTemporalAA.usf and change both lines 319 and 348 from "#define AA_YCOCG 1" to "#define AA_YCOCG 0"
It might cost you a bit of performance maybe, depending of your game, but maybe it can fix it?
answered Nov 30 '18 at 10:40 PM
Follow this question
Once you sign in you will be able to subscribe for any updates here