It is caused by the fact that ray-traced lighting techniques such as lumen accumulate over several frames. When you move backwards, you are revealing lots of surfaces that were not present on the previous frame and so there isn’t any lighting data for it to reuse. Usually this doesn’t cause any noticable issues - But when combined with flickering / rapidly changing light conditions it does. While increasing lumen quality settings might reduce it, you probably won’t be able to eliminate it while using Lumen / ray-traced lighting.
Usually this is caused by not having any surface cache so you get screenspace lighting gibberish
Show the Lumen debug views
can you tell me another good alternative like Lumen if there are any please?
Ok so reducing the r.Lumen.ScreenProbeGather. fixed it for me. You can change it with this “r.Lumen.ScreenProbeGather.Temporal 0” command.