Using Android 12 and Chrome, when I logged in to gmail.com, I got a new email notification from a Gmail app installed on the same device but never accessed by me.
How did supposedly secure Chrome leak my login to this Gmail app?
(And I can't remove the emails captured by the Gmail app from it. Despite removing the Google account from the device and disabling the Gmail app, when enabled it still shows my emails.)
UPDATE: This report is incomplete, omitting to mention that immediately prior, I'd logged-in to the Google Play Store app (to get Chrome). See my own answer below.