Sorry to hear you're having this issue. It's unfortunately not one that I have seen before, but I'll see what I can do. If you are on Windows I can take a look, unfortunately, Mac support is not really possible anymore.
If you could send me the save files at "C:\Users\'User_account'\AppData\LocalLow\OwenBellGames\Mendel" I'll see if I can recreate the issue with those.