Spektrum DX5e enters comatose mode. Binding to Ember fixes it?

[HobbyJumper]

This is a weird one. Every so often I turn on the DX5e, connect the flight battery in one of my AR6115e equipped planes and it won't bind. Just sits there. Even though it was working great minutes, hours or days ago. Same result for each one I try. Rebinding doesn't work.

The way to fix it, I have found, is to turn off the Tx, plug the flight battery into my old Ember2 (!!) then turn on the DX5e and bind to the Ember (which works every time). Then, unplug the Ember, leave the transmitter on and voila it will bind to all my other planes no problem.

The original problem may takes weeks to reappear.

What the heck is going on?

Thanks!