Sorry to hear your having problems with the link system. We had the same problem with our 2014 Bighorn, not long after purchase. Tried everything I could on my own, as you have. There is information on the Lippert web sit on how to reconnect the remote. There is a black button on the board. Hold it down while pushing the "light" button the first screen of the remote. If it works, you should hear a click. But that didn't help in our case. Ended up have to take ours to the dealer for replacement of the board.
Has worked properly since the repair was done.