# BACKUP
# apt update
# apt upgrade
# nano /etc/apt/sources.list.d/armbian.list    ->  comment out the armbian repo
# nano /etc/apt/sources.list   ->  change to debian bullseye repositories

# apt update
# apt upgrade --without-new-pkgs
# apt full-upgrade
# reboot

 

# nano /etc/apt/sources.list.d/armbian.list   -> reenable armbian repo
# apt update
# apt upgrade 

#Leave a like if it worked.