You hero!! That 8000000000073 was definitely the culprit after downgrading from useless 21.0.0+ back down to stable 20.5.0 trusted you that much i didn't bother making a backup 😅
Okay, I managed to recover my emuNAND data. I don't know if it will work for everyone after downgrading from 21.0 to 20.5. The bug is 2162-0002 1000000000025.
You will need to launch tegraexplorer.bin via Hekate.
Tuto: Warning: always use eMUMMC...