Issue with internal device communications?

[RF_Burns]

I have been having some issues with keypad switches (2486DWH8). In one instance I have 2 keypads and one single switch linked together to turn On some stairway lights. It worked  fine for several years. One night I pressed the Main button on the keypad (which actually powers the lights) and the lights did not come ON, however the keypad buzzer went off and the Main button lit up. The other switches responded indicating they received the communication that the lights were turned ON.  I went to each of the other 2 switches and they would not turn ON the lights either, although each one's button lites responded.

I got out my laptop and logged into my ISY994 and was able to control the light via the keypad address which power the lights.  I can also manipulate the other switches.  Its as if the signals telling the power circuit to turn ON do not get to it, although the switches respond. However I can control the power through the ISY!

I tried numerous things to get it working (restore device, removing and re-installing devices in scenes, hardware resets and reprogramming). Finally I simply rewired the power through a different device (since 2 of the devices were originally 3-way switches). The original (faulty switch) can still communicate normally with the other two switches.

Recently the keypad on my bedside table no longer communicates with either the bedroom or bathroom wall switches.  I've done the same restore, reset etc, but it does not talk or or respond to the other switches in its scenes. I cannot see the state of the buttons change through the ISY including the Main button. However I can control the Main button and its button responds from my laptop through the ISY.

Anyone have an idea what is happening or a fix?

Thanks