I believe that google login cookies, are persistent cookies with a longish max-age/expires value, so that is not surprising, and hence why you have to use google periodically to "refresh" the cookies.
Here is what MDN[1] says about session cookies:
> Session cookies — cookies without a Max-Age or Expires attribute – are deleted when the current session ends. The browser defines when the "current session" ends, and some browsers use session restoring when restarting. This can cause session cookies to last indefinitely.
I was unaware of the "session restoring" point. This has to be considered if wanting to "unforget" the use of session cookies.
Here is what MDN[1] says about session cookies:
> Session cookies — cookies without a Max-Age or Expires attribute – are deleted when the current session ends. The browser defines when the "current session" ends, and some browsers use session restoring when restarting. This can cause session cookies to last indefinitely.
I was unaware of the "session restoring" point. This has to be considered if wanting to "unforget" the use of session cookies.
[1] https://developer.mozilla.org/en-US/docs/Web/HTTP/Cookies
(edit for layout)