I'm having similar problems. My setup is 2 x TL300 tail lights, 1 x RTL 510 Radar, 1 x UT800 head light, 1 x Edge 1000, 1 x Varia remote, speed and cadence sensor bundle, heart rate monitor. All in all this is an expensive setup, so given the expense and the fact that Garmin are a technology leader you would expect the setup to work flawlessly; alas this doesn't appear to be the case.
When setting up the light network on the edge 1000 with all lights included and the tail lights and head light paired with the Varia remote, I find it impossible to get the setup to work properly. The light network forms, then breaks, then reforms, then breaks causing the lights to turn off then on again, drop out of the network and functions such as the turn signals to fail.
We need a clear statement form Garmin, can the Varia remote co-exist happily with a Varia compatible edge unit such as the 1000 or not???
I've invested heavily in a Varia setup to improve my safety whilst cycling, but in it's current unpredictable state it appears positively dangerous.
How do I get a formal response from Garmin????
This is a serious safety issue that needs addressing!!