Incorrect creature in stable group

IOS
Ver 1.3.5

This problem seems to start this version.

In my stable group, the spider occultist (slot 2) keeps getting replaced by a unicorn vivifier. There is a vivifier in stable and it was in the exact same stable group like… 2 hours into the game. Taking out the incorrect stable group, leaving the unicorn and bringing up the menu fixes the problem temporarily.

I have tried saving the group to a different slot. Didn’t help.