Folks, not sure if this applies, but I had a frustrating experience when putting my D2 into a newly set up bedroom system after it sat for a while since I upgraded to the T2. I use the phone to control the D2 in the bedroom and the iPad to control the T2 in the main system, and it came down to having different wifi networks auto-joined by the phone and iPad.
Simply making sure that the LUMINs and all of my iDevices were on the same network solved my problem. Like I said, it might not apply here. If it DOES, Peter or someone who is more tech-savvy than I can explain how to set up your network.