Gateway at 192.168.20.1 was being provided via DHCP as the NTP server but does not serve NTP, causing NodeClockNotSynchronising across all nodes.
systemd-timesyncd was installed via common_packages but never enabled or started, causing NodeClockNotSynchronising alerts across all k3s nodes.
Signed-off-by: Tuan-Dat Tran <tuan-dat.tran@tudattr.dev>