Had a Centos VM that kept slipping time. Every week it would loose about 30min. No amount of NTP syncing got the time correct until manual intervention.
Msp couldn’t work it out, couldn’t rebuild the server for infrastructure reasons, and only that server had the issue. The other 3 VMs on that host were fine.
Cron job on one server took it current time, sshed to the dodgy server and configured the correct time.