@nilsholgersson pcsx-rearmed is known to have a lot of compatibility issues, being fast enough on arm processor came at a cost... and don't expect fixes for this, notaz (the main developper) has been quite inactive for years.
Your best bet is to use either the original hardware or a more accurate emulator (i would recommend beetle-psx-libretro) on a hardware more powerfull than the pi (i would say something with a cpu as close as possible to 3Ghz)