So were the 2 wireless client boxes working before you installed the 2 TVs? If they were, when you powered them back up, they should have automatically connected to the HR-17's built in video bridge. If that didn't happen, its a DirecTV problem.
That extra video bridge you found 'unpowered' should have stayed that way (and removed from the system so it never got powered back up again). It could be that you powering it up, caused the wireless clients to jump to it. And now they expect to connect to that only, which no longer works correctly for that type system (Genie 2). So you stepped on a landmine, should have left that alone.
Only other thing to try is: Remove that video bridge. Power down the server and clients for 10+ minutes. Power the HR-17 server back up 1st (give it 6+ minutes to completely boot). Then power 1 wireless client back up (give 2+ minutes). Then the other wireless client. See if they will work then. If not - DirecTV problem.

So yes, they need to call DirecTV and have them fix it for free (it's their service). Or they can pay me 'however long it takes' to try and fix the problem. But in your circumstance (and if the customer can't use wired boxes), I would absolutely bounce this to DirecTV to fix 'their' problem.

Again, being how many issues I have seen with those wireless POS boxes, I really wouldn't want to mess with that system unless wired boxes could be supplied. Other than trying the quick basics, let DirecTV handle that wireless BS.