xyzulu This wasn't the issue this time.. plus Enhance not restricts mariadb repo to IPv4 I believe.
Can’t comment on the issue this time, the upgrade went smoothly for us. But we’ve had problems before with some repos like MariaDB and GoAccess, which turned out to be temporary IPv6 connectivity issues. If that’s the case, you can force IPv4 with:
sudo apt -o Acquire::ForceIPv4=true update && sudo apt -o Acquire::ForceIPv4=true upgrade -y