Proxmox VE does not set the system time after the start.
The system time will be provided at OS starting from the BIOS/UEFI as it is on a Baremattel machine.
If you have time jumps check your timeservers if you have NTP configured.
I never saw time jumps on a default configured Windows.
If you have a case where this scenario is reproducible, we will look into it.
OK, but... I do "the thing" and then problem is solved .
Some is wrong with the time control at baremetal?
My PVE catch the ntp information from internet and the date time set is OK at PVE OS; but, if I add a Windows Server 2k8r2 machine (VM) and I set "os type" as Linux the clock jumps like a saltamontes. Then if I set flag as "Windows 7/2008r2" the clock is OK.
VM has not internet connection, no ntp server associated.
Baremetal time is OK always.
Windows (desktop anyway) generally likes the motherboard Real Time Clock to be local time, whereas Linux prefers it to be UTC. If you set it to the wrong one, Windows time service will eventually fix it for you. Which may not be what you want. There's some registry keys you can Google to make WIndows use UTC if that's what you want.
In your first screenshot you have "Use local time for RTC" set to "no".