send me a copy of the save; it'll help me work on a fix.
I already did.
the mega link in above post is the link to the save. There are examples nicknamed broken as well as possible to reproduce the problem reliably by using harpy in the farm and slime as a stud (most offsprings so far). Sometimes it may take a few times as it's slightly rng. Had 1 time 5 with bloated harpies and 5 not bloated slimes shown as harpies in family tree. I didn't test the 25% yet.
Hope it helps to find the solution.