Foliage brush erasing but not painting?

Hi,
Was hoping someone could advise on a foliage brush problem…

My foliage brush has suddenly stopped painting, it will erase the foliage already there but not paint anything. The foliage count still goes up when I try painting but nothing is there. I’ve tried changing all the mesh settings, ensured the mesh is ticked, landscape filter enabled etc. and nothing. Has anyone else encountered this?