Moving wireless UVerse box from room to room - DirecTV

When moving our wireless cable box from room to room on occasion the sound on all channels will disappear and usually returns after rebooting or swapping out HDMI cables, not new ones just another cable which we reuse from previous issues. Also, we have two wireless cable boxes and sometimes swapping those out with each other solves the problem. All this after several wireless reboots and reboot of the gateway as well.
Would like to understand why this happens and why it is so difficult to move wireless boxes around when that is the whole point of having wireless boxes, ease of movement around the home.

This question, "Moving wireless UVerse box from room to room," is about DirecTV channels, programming, equipment, and sports.