Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Thanks. I had exactly the same problem. Changing mtu (and other workarounds mentioned here) didn't work for me, however changing DNS did. Changing it in network settings worked and also in NordVPN's "advanced settings". In the end I left the network settings as they were originally and just use the feature in NordVPN's Windows app.