Old system is different from new - Within the old, you had to put in a smudge.
If you have the layer system enabled this may not be the case - it’s supposed to work with removing visibility to activate different things in a non-destructive way, so if I were to create something like it I’d get all the layers I need up in vram ready to go…
With all systems, you should actually be able to enable the landscape layer debug view to visualize if any part of it is painted by a layer.
I have no idea how or if this works on UE5 - I stopped using landscapes eons ago because of their low performance…
Anyway, glad you sorted it out 