Per [1], there was a related issue affecting Cloud Console operations globally, starting from the point where the incident went regional at 23:00 PDT, and lasting until 02:00 PDT-ish. It is incorrect to say that this had zero impact elsewhere.

Sounds like some global control plane related to instance management operations started returning errors once one region failed. Or perhaps it was just the UI frontend?

[1] https://status.cloud.google.com/incidents/BWK7QzFBmfaZ4iztke...