We have been replacing all our light switches with Insteon Smart Switches (http://cache-m2.smarthome.com/manuals/2477d-en-03-26-2015.pdf page 11) to control them via our phones. Ultimately, they work they hookup the same way as regular switches except for 3 way and more switches rather than using a traveller to connect related switches that process is done wirelessly so travelers get capped line goes to hot, and load goes to cold. We've set everything up successfully except for one location.
It use to be a ceiling fan (light and fan) but we previously replaced it with just a light. It's 3 way, so one 2 gang has a switch for the light and previously connected fan, and the other gang also has a switch for the same light and the previously connected fan.
On the ceiling light there is a red capped off and a black attached. And of course neutral and ground.
Does anyone have any thoughts on what I can test or get to the bottom of this or more information I can provide? Thank you!