Yes set:
r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal to 0
and then if it doesn’t help completely, keep increasing the value of:
r.Lumen.ScreenProbeGather.Temporal.DistanceThreshold
This cvar defaults to very low value, but you can keep increasing it until around 100, before it starts to cause severe artifacts.
However keep in mind that both of these, especially the latter one will be a bit of a tradeoff. You may lose some accuracy in some simpler areas which don’t have the dense foliage geometric detail, where lack of GI accuracy isn’t as visible.
You may want to start by disabling “affect distance field lighting” on that grass though, and only resort to testing the cvars afterwards.