When I connect to a VPN my Ubuntu laptop calls to an ip address BEFORE CONNECTING and the whois is:
inetnum: 185.125.188.0 - 185.125.191.255
netname: UK-CANONICAL-20151111
country: GB
...
organisation: ORG-CGL14-RIPE
org-name: Canonical Group Limited
country: GB
org-type: LIR
address: 5 New Street Square
address: EC4A 3TW
address: London
address: UNITED KINGDOM
What is this and why?? Why does Ubuntu check in to Canonical HQ when I connect to internet??
It’s almost certainly related to cloud-init, (the canonical tool for handling deployment automation) or Ubuntu pro (extra long support for backporting security packages to older distros, plus some conveniences). They’re pre installed as a convenience to paid users of those services, that’s the (IMHO, quite reasonable) model they use to fund the distro. I would expect that some or all of that traffic would disappear if you disable/remove those two services.
https://cloud-init.io/
https://ubuntu.com/pro