You've tagged 21.10?
Why are you trying to install Ubuntu MATE 21.10? It's EOL.
Refer
- Ubuntu MATE 21.10 reaches end of life
- Ubuntu Fridge | Ubuntu 21.10 (Impish Indri) End of Life reached on July 14 2022
I'd check your release, the 21.10 tells you it was the 2021-October release, as Ubuntu releases use a year.month format (2000 is added to the year), and 21.10 wasn't a LTS release so installed systems upgraded to Ubuntu MATE 22.04 LTS before it reached EOL.
I'd suggest instead installing a supported release, and not worry about issues with an EOL release.