The G9 is on Android 11, Motorola never bothered to update it to 12
(part of the reason I got a Pixel 6) - I haven't tried it again since
the most recent update so not sure if it has been fixed now.
I can confirm this is STILL an issue and has now been for months. I had
to use my old Motorola phone to set up a new Google Nest Hub Max today
as my Pixel 6 just told me it "needs to be registered" - also seems to
be an issue with new Chrome Cast dev...