My foliage will not cull since 4.15.0

This test needs to be done in a completely new and blank project using simple/minimal content. The project you are displaying is actually content from the Kite Demo and not from the Starter Content pack.

I just tested it again using the starter content and a very simple landscape material with only a flat color with the layer. The culling is working as intended

Cull Distance

Cheers,