Xbox 360 kids activity in Microsoft Family not showing

I have been using Microsoft family successfully to manage and monitor 2 children's activity (both logged in with separate Microsoft accounts) on a windows 10 PC. We also have an Xbox 360 console which we are signed into using our Microsoft accounts (me as parent and kids as kids) but the Xbox still isn't listed in the devices and therefore cannot be 'controlled', time or activity wise.
I've tried to manually add the 360 to Microsoft family devices list and it shows up but when looking at the kids devices it is not shown, only the PC is shown.

Its like the 2 aren't properly linked! However if I check my microsoft account I can see purchases I've made on the Xbox using my credit card, so there is some link?!?
Anyone any idea how to link the Xbox correctly or why its not showing in the kids devices list?

Thanks Kelly

:)