Have problems with this as well and hard bunny poop basically when going RFL. Fat and protein don't equal fun pooping.
What worked for me:
-Eating your vegetables and getting your fiber in. It's a chore for me sometimes on RFL, but it definitely helps.
-I take Zinc, magnesium, calcium pills and those help as well. Be careful with magnesium supplementation. I've found it can make me very sensitive to having diarrhea. I'd try a low dose and see how you tolerate