Yes, I am experiencing the same problem. I use an R4 v1.15, with Kingston 2GB "Made in Taiwan" MicroSD. I've tried formatting the card, and starting the game brand-new. No luck.
Not sure about other models of Pi4 but the Pi 4 B with 8GBs OCed to 2Ghz handles PSP really great except like 1 game I found and it is playable it just looks bad lol Motor Storm Arctic something or other.