Excel 2019

I have Excel 2019 on Windows Server 2019 on a virtual server NOT tied to the Internet.  Excel does not respond (Not Responding) every 40 seconds.  Works for 20 seconds.  No Add-ins, not responding if run as an administrator, not responding if run in safe mode.  Same not responding if run w/o firewall or antivirus.  I told it not to update or look for updates.  It does this w/o having an open file. Any ideas what can be done to isolate the cause or correct it?