You may have found a bug that we missed. We would be very grateful if you could upload your save file(s) to this link so that we can analyze in depth what is causing the problem.
https://www.dropbox.com/request/iAEFvUrZelO5bsfafcoY
The save file is stored here:
Win: {Game_Folder}/saves/
Win: C:\Users\{user_name}\AppData\Roaming\RenPy\Heroes University H 0.1.5.1\
Android: /storage/emulated/0/Android/data/com.huh/files/saves/
Android: /storage/Android/data/com.huh/files/saves/
Mac: $HOME/Library/RenPy/Heroes University H 0.1.5.1