we do now have a proxmox-backup-client repo that just contains the client .deb for Debian/Ubuntu based systems:Seems to be fixed by v1.0.13-1 release. Upgraded the package on both hosts and the backups are flowing again, thanks for fixing this bug.
However, can't wait for the static binary to be available!
https://pbs.proxmox.com/docs/installation.html#proxmox-backup-client-only-repository