okay a few things to try when this glitch happens...
1. lower the decay influence in the hair gen node(I had mine on 10 and lowered it to 1, this fixed the problem)
2. disable the guide groom (the lift, cut, etc brush tool) inside the guide groom.
3. disable the partition guide node in the guide groom node. Also note that the guide partition node doesn't work on hair clumping, if you have hair clump nodes in your hair gen it will break the guide partition. The alternative to using a guide partition is to split the
groom into different groups.