I attach 2 images
you should be more specific. but I’d say it’s the Temporal AA
Turn on LOD visualization and see what LOD level they are rendering at. You can adjust foliage LOD if they are placed with the foliage tools. (r.foliage.loddistance or something)
Temporal AA wreaks havoc on all kinds of tiny details, it’s especially apparent with tree leafs and fronds. Needles are the worst case scenario pretty much.