it could be your config.txt. did you post that somewhere? what does it look like?
I don't know what nonpdrm_un.skprx is.
I looked for the config.txt in the ur0:tai folder and it looks like this :
View attachment 233598
The very last line 0032 reRescaler might be what's causing an issue for graphics, but I have no idea where it comes from, is it a plugin? I used a native resolution patch for GTA in the PSP plugins I don't know if that's the one.
I noticed that there is a reRescaler.suprx file in the tai folder, but again I don't know where it comes from and would like to try to disable it.
0syscall6 stops my music app working ....... no idea whyDon't use ReF00D, it's been superseded by 0syscall6.
Github page of ReF00D even tells you to use the latter.