Use of remote port on A77 causes buttons not to work?

[Pam]

I have a Sony a77 ... I've been hired by Evolve (similar to AirBnB) as a real estate photographer. They require an AEB of 5 frames at 2.0EV. Of course the maximum at a77 can shoot is 3 frames at 2.0. At their instruction, I'm shooting 2 sets of 3 for each angle  (+4. +2, --, and then moving the exposure over and getting --, -2, -4). That is fine UNTIL, randomly, none of the buttons on my camera work and I can't change the exposure! I feel like I've narrowed it down to it happening when the remote shutter release is plugged into the remote port. But sometimes it works fine and other times the buttons will not work! Any ideas??!?