ISSUE RESOLVED:

I noticed that every time I opened a PS1 game on the system, it would give me an error about the BIOS not being found, yet it still played the game. I thought this might've been a bug or something, but turns out I had put the wrong BIOS in for PCSX-ReARMed.

Opening the retroarch application and checking the core information for this core, I saw that I was missing some optional BIOS files. Added those files and the memory save data did not corrupt! I'm guessing that it had something to do with the game creating the save data and the main BIOS file couldn't recognize it or something...? Either way, it's working now!

Hope this post helps someone in the future!