TOPIC:

From the nanoAVR DL User Manual:

5.4 GENERATING CORRECTION FILTERS

The Dirac Live Calibration Tool For miniDSP will contact the Dirac license server to verify its license,
so you will need to be connected to the Internet to perform this step. If a firewall is in place, it must
allow HTTP (normal web traffic) to pass. Otherwise, an error such as the following may appear:

Is this something that Dirac Live will do every time I perform measurements for room correction? Or how often does it do this?

It's exactly as per this step of the process. (i.e. when you try to generate filters). You will need an internet connection at that time.

DevTeam

So it will only need to connect when I make changes to my setup?