There is high and low versions of the meshes and scenes. I’d suggest using the lower resolution ones. Also wpo plays very big part performance-vise so when using foliage tool remember to set the world position offset visibility distance to something else than 0 (no wpo culling) or if no animations needed then disconnect the wpo from master material completely. Even when using Nanite the foliage culling distances still matter so decreasin those values helps as well.
I’d say editing the visibility distance or disabling the world position offset animations are the quick fix.