UE5 Lumen lines/streaks artifact

[Arkiras]

For what it is worth, Daniel Wright responded with a workaround in that thread last night:

Lumen GI and Reflections feedback thread

This is a bug that made it into release, you can work around with ‘r.Lumen.ScreenProbeGather.IrradianceFormat 0’

Worth seeing if that fixes it for you