Office producing certificate error re: nrb.footprintdns.com domain

I have had exactly the same problem with excel in office 365 over the last few days and it is a massive nuisance. I leave a Win 10 machine running some excel VBA macros all day long unattended however the process stalled for the first time in a year yesterday and an accumulation of these Kaspersky messages is the only unusual related activity.

The footprintdns.com domain is registered to Microsoft and the randomised sub domains means I cant easily block the URL in the Windows Hosts file so its a huge nuisance! I saw some references to older threads on the web asking microsoft for information about their use of this domain but they never responded. Just seems to be unnecessary snooping at best and possibly intermittently causing me a more serious problem in intermittently stalling for my previously very stable Excel VBA macros.