Hi adhills,
Is that in 5.2? I had similiar issues, but it was fixed in 5.2. For 5.0 and 5.1 there were many issues with foliage, so it wasn’t a good idea to try with those - but 5.2 seems to be a lot more robust with foliage - just make sure you have WPO disabled at a distance in a similar way to culling.