Hi guys,
I’ve been using ue4 for a whie now, coming over from UDK, and I’m loving every minute of it. the community and documentation haven’t failed to provide me with an answer yet, but i’m having trouble finding anything about what im experiencing 
I’ve been using the foliage tools with absolutely no issues until yesterday; I am trying to paint my foliage using the landscape layer options, and this worked fine until I reimported my grass meshes after a minor tweak, changed nothing major about them at all, just optimising them slightly, and creating some additional LOD’s for a smoother transition. However, now, when i go to paint them, even with the layer set to ‘Grass’ either in a created foliage setting asset, or just in the paint options, they seem to ignore it and paint on all layers.
They paint perfectly well without the layer setting enabled, but when i try to use it, the density seems to be cranked up and it just paints on all layers. This is not restricted to my grass meshes either, it now does this with anything i try to paint, including trees, rocks etc. I am at a loss here, because yesterday they were working, and now theyr’e not
Am I overlooking something blindingly obvious here? 
P.S. I can provide screenshots if necessary, I’m currently away from my computer however, so i can post them when i’m back if need be.
thanks in advance, Josh.