I just tested that it works for me.
Please verify that the “Check for Firmware Updates” option in Lumin app is set to Yes. Then double tap iPad home button, swipe away Lumin app to kill it.
Power cycle both the Lumin units.
After they are booted up, launch Lumin app again.
If that still does not work, please try Safari on iPad and check whether it can show http://www.luminmusic.com