This morning I logged into Google Cloud Platform, navigating to Compute Engine. Most of the external IP addresses in the VM instances are now ghosted - "Allow HTTP/HTTPS traffic" has automatically adjusted itself (not selectable) in the details of these instances.
It is worth noting that this hasn't happened to all instances, however the External IP addresses that are selectable now point to a "https://" address instead do of the usual "http://" (causing me slight heart failure this morning).
I can still login to the relevant admin/back-ends for each site, and phpmyadmin is unchanged, so still have access here.
Why has this happened and do you think I can expect further changes without notice?