Okay I am super duper sorry, I have no idea what's causing that bug I honestly can't figure out what it is or how to replicate it on my end so I'm really sorry! Not sure how to fix it in the slightest
Ok, it must be something with my Windows 10 installation.
Out of curiosity, I slapped the game in a "Windows XP x64" Virtual Machine and it runs perfectly fine in there. I could even save.
Very weird. Welp, gonna play in a VM then.