Windows Time stops when logged out

Hi everyone

I have been using Teamviewer Business for some time to allow remote access to a series of Windows 10 laptops and industrial PCs that are deployed in distant locations attached to noise loggers.  The machines allow remote access to the noise logging hardware, as well as access to the data being recorded.

I am having an ongoing problem with one machine where the system time completely stops advancing when I am not logged in via teamviewer.  It even stops advancing if I am logged in, but have the teamviewer screen minimised at my end.  I have tried the following:

• All manner of options in the system time settings, eg. Set Time Automatically both on and off.  It does sync with internet time ok, but loses sync if I log out.
• different internet time servers.
• Check that Windows Time Service is running
• Ran a system scan (no errors)
• Ran windows update
• Installed a third party time sync app "NetTime".  If I set this to sync time every hour, the log will show that every single hour, NetTime has to add 1 hr of time to re-sync.
• Check power settings, everything is set to go to sleep 'never'

My PC is a Fitlet2 Intel Atom E3950 1.6ghz running Windows 10 Enterprise 2016 LTSB 64 bit.

Any suggestions are most appreciated!

Thanks,

Matt