You're close, it would be
ha-manager remove 108
. As the id of a vm/lxc must be unique regardless of it's type it is sufficient to just provide the number.
regarding the error message of the uninitialized value: check the required services are active (running) with command
systemctl status pve-ha-crm.service pve-ha-lrm.service
if not:
systemctl enable --now pve-ha-crm.service pve-ha-lrm.service
btw: starting a container with debug output is also possible with
pct start <id> --debug
Is there a reason why you deployed the container as privileged? Try deploying it as unprivileged container, this is more secure way and should be default.