But your PROXMOX doesn't run under Debian?
If you use cloud-init, is need to change a parameter to set hostname persistently. Is the /etc/cloud/cloud.cfg file, and you need to change the preserver_hostname directive to true, as:
Try to reconfigure the old hostname...
The cluster service was stopped.
root@pxmx-uno:~# systemctl start pve-cluster
Job for pve-cluster.service failed because the control process exited with error code.
See "systemctl status pve-cluster.service" and "journalctl -xe" for details.
root@pxmx-uno:~# systemctl status pve-cluster
Has version 5.1.30 and when try to update to 5.2.10 just break web interface.
Try to use apt dist-upgrade, but doens't work.
Configurando pve-manager (5.2-10) ...
Job for pvestatd.service failed because the control process exited with error code.
See "systemctl status pvestatd.service" and...