Business Ethernet Issue

What DirecTV DVR/Receiver models do you have?

Are you sure this is a DirecTV issue?

I have had Comcast out twice and 4 different modems amount multiple tests.  

direct tv box is h26/500

each tv has a connected home adapter 

So you have two Ethernet cords that you keep swapping between 16 DirecTV boxes?

Regardless, plugging something in by Ethernet should not kill the WiFi of your router. That sounds like your router has an odd issue or setting. If all 16 TVs were wired in I would wonder if router isn't good enough to handle that plus WiFi, but up to two at a time shouldn't be an issue.

Once sorted out what in the chain is causing the issue you might consider a good Ethernet switch to connect to your router so you don't have to keep swapping Ethernet cords around and just have one to each DirecTV box.

I have Comcast out twice and they have swapped mod multiple times.    All 16 TVs run back to central location and into 2 connected home adapters and each of those adapters have an Ethernet running to the modem.   

Not sure why there are two DECA BBs or Ethernet cables needed at the router/modem, DTV is not made to have more then one connection to the router/modem and not sure why DECA Home Adapters are needed on the H26s as they should have DECA built in..