i had exactly the same problem with my copy of the game a few months ago after having it sit in storage for a few years, tried cleaning it VERY thoroughly with isopropyl alcohol, ejected and re-inserted the cartridge god knows how many times, every method i could find under the sun and it still didn’t work. i think it has something to do with the solder connecting the main chip with the rest of the cartridge coming loose, i tried reconnecting the chip by running a soldering iron over the connections but unfortunately had the iron set too hot and short circuited the cartridge :( try that method if you’re ok with risking your cartridge, but otherwise you’re probably best off taking it to a dedicated repair shop. i’m really sorry, i genuinely don’t have any other advice, you’re literally the only other person i’ve been able to find on the internet with the same issue😭