how to list devices attaching via Extender

Hello - I have the Nighthawk x6 r8000 router and Nighthawk x6s ex8000 Extender. All is working as expected and the deadspot in our detached garage is no longer a deadspot. Super strong WiFi signal !!!

However I have a couple "How to" questions. 

1 - Is it possible to see a list of devices attaching to the router via the extender? The devices going thru the extender show up as attached directly to the router in Genie and the Web Admin Interface. I know they must be going thru the extender because when I turn off the extender the connection goes from All bars to one bar and connectivity is horrible.

2 - Why does the extender show only one of the two 5GHz bands as available? I can see the 2.4GHz band and one 5GHz band only.

I love this extender but not the admin interface.

thanks

al