I have installed the beta version on both devices and the the Pixel 3 is listed is Mobile Security in My Web Console and TAB S2 is not listed.
I have reinstalled a couple of times, including wiping the cache partition before a reinstall.
The TAB S2 is a SM-T815Y running Android 7.
Any ideas please?
Best answer by SXR6
I have come up with a workaround.
I added a new user to my console with a different email address and was able to add the tablet to this user.
Thank you again for your help