I regret to inform you, but the cartridge is fake.
After looking at the listing, I can see the following red flags:
- The seller has multiple of each. These games are unfortunately really hard to get your hands on in bulk.
- It’s listed as “new” condition. Pokémon games this old are never new unless they’re reproduced.
- It says it’s not original cassette, aka, not authentic
I can’t comment on the price since I’m not fluent in the currency. Hopefully it wasn’t expensive, though. Typically, repro cartridges are cheaper than authentic.
This is 100% the source of your problem. Reproduction cartridges are made by importing the ROM. There’s all sorts of errors that come with reproduction cartridges, the majority of them being silly and random like this.
There’s unfortunately there’s nothing you can do, since this error was created when they copied the file onto the cartridge.
Here are things I suggest:
- Contact the seller. They can send you another one if you explain the issue. This won’t be the case for all reproduction cartridges; you just got unlucky and got a bad one
- Buy an authentic one. A bit more pricey, but you can get authentic ones on eBay for as low as $20 if you get a Japanese cartridge.
- Start a new file, with plans of only catching 6 Pokémon. Since you can’t fix the issue, why not make a fun challenge of it? You can still play, just not access the PC. Plan your team in advance so you have a flier and a surfer.
Sources: I’ve had really bad reproduction cartridges too. It wouldn’t let me open the Pokémon menu on mine, for no particular reason. I collect a lot of cartridges. Also skimmed Bulbapedia for any known glitches; there were none.
Hoped this helps! Sorry about your cartridge :(