I have several Lubuntu guests, on Windows hosts, that have kept their time the same as their hosts' time for years. I've actually never had one NOT have the same time as the host.
Today I noticed one Lubuntu guest's time was about 12 minutes behind the host. Have had this guest for years without trouble. I do know the time was correct on the guest 6 weeks ago (I just happen to have screenshots) so the time drift has happened since then.
The parameter to sync to NTP is not checked on any of my guests. Today I marked it on this guest, the time updated, and I have again unmarked it.
What would be the cause(s) of the guest's time falling behind the host, when that option is not marked? I don't mind enabling NTP if that's what I need to keep the time correct. I'd just like to understand what happened.
Guests: Lubuntu 22.04 plus all patches, Host: Windows 7 pro all patches. No intentional changes to either in the last several months.
Thanks for any info.