I have had two CT100 thermostats installed for several year and paired with my 2Gig Go Control 2 with no problems. I frequently use the alarm.com android app and an echo to control them. Last night my upstairs unit apparently lost the ability to be controlled by the Go Control… The link indicator was still on the thermostat. I ultimately removed the device from the controller and re-added it. It was discovered with no problem, but the query function apparently did not properly identify the device, so it was shown as unknown and could not be controlled by the controller. Both thermostats have the C wire. The failing thermostat is functioning fine except for the connectivity. The failed unit is not far from the controller, but I removed the controller from the wall anyway and placed it directly next to the thermostat with exactly the same result. I read another thread describing this problem but did not see a final resolution. I know the device is no longer supported unless it is grandfathered in, but mine are grandfathered. Can you help me resolve this. I do have considerable experience with z-wave devices and am confident I am performing the functions properly.