Sorry, I have not needed to do a MAC clone in years. The last time I did I was still using a “burner device” to make things work as described above.
These days many devices have “Private Wifi address” to change mac to reduce tracking. If I were to try this again I would think about having it disabled when I first registered with the Wifi service and then enabling it after doing the mac clone on Gl inet router to have it take over.