This is my favorite. And the code popping up in a separate window on the SAME device!!!
You (and others) seem to be confusing the device verification with the *browser* verification.
These 2FA alerts are for when you log into a new (or recently updated/modified) *browser* on a device - which can be the same device linked to your iCloud Account... or not. It’s not the *device* you’re authorizing!
Faux outrage...