Harmony 900 universal remote and apple tv

Anyone out there successfully able to set up a harmony 900 with apple tv?

I'm trying this on harmony site, but hope there might be someone in this community with some insights.

here is my problem:

Set up a new Harmony 900, based on the settings I (successfully) used for my 890.

I'm getting a problem with my Apple TV.

I set up a new generic activity, "Watch Apple TV".

All the settings are right with the inputs on the tv, av receiver and Apple TV. So I click on the activity and up pops Apple TV, as expected.

However, when I try to control the Apple TV nothing happens. But if I click on devices, then select the Apple TV device, I have full control --i.e. the remote works as expected. But as soon as I click off that device (i.e. go to "current activity" or anything else, I lose the ability to control the apple tv.

Furthermore, when on this activity, I cannot control the volume (normally done through the av receiver) unless i also click on devices, then select the av receiver.

I tried pairing/unpairing the remote, as per Harmony FAQs (FAQID=1245).

Any suggestions? Thanks in advance.