Hi guys,
I've been struggling with a very weird issue for the past few days and I've reached the point where I need to ask for help before I go insane

Basically, I have an original cartridge of Pokemon Y but I've also got the game installed as a CIA on my N3DSXL. I've started a new save on the cartridge and noticed shortly after starting the game that it always crashes with a generic ErrDisp screen when I equip a specific piece of clothing on my character. At first, I thought it was a problem with my edited save file but I imported that very same save into the CIA version of the game and there it works perfectly fine.
So I figured that I am dealing with a corrupted cartridge and GM9 also can't verify the cartridge, which seems to support that theory. Now I ran the cartridge fixer a number of times but the end result never changed. The verification doesn't work and the game still crashes with that same ErrDisp screen.
Now I've enabled logging in the cartridge fixer for the last few attempts and now I'm even more confused.
I have 15 logs and most of them contain nothing except for
"CORRUPTION FIX LOG ON C:/0004000000055E00_v00.3ds"
which I figure most mean that the cartridge is actually okay. Some of the logs additionally contain
"
Unfixable: 5008c000
Unfixable: 5008d000
"
though. Does that mean my cartridge is unfixable even though that error doesn't show up in every attempt?
I've also tried reflowing the solder joints of the NAND chip but didn't change anything.