I suspect the answer from Dish is correct, that
at least one of your receivers were hardwire to the TV or TV's; but more specifically, all of your receivers are not feeding a home distribution system, particularly those that are feeding a TV directly.
Depending on which receivers you have, you may not be able to put all of the "satellite receivers TV1 and TV2 outpus" on a home distribution system.
Reasons...
- The 311 has a single output on either Channel 3 or Channel 4.
- The 322 has two outputs, but TV1 can only select Channel 3 or Channel 4.
- The 522 has two outputs, and I believe it is also limited on which channel TV1 can output on.
Someone may clarify this, or I may check the 522 documents later and then edit this.
Now if you had 2 ViP622's, you could use 4 different channels and put all 4 outputs (2 TV1's and 2 TV2's) on a home distribution system and they will not interfere with each other, as long as there is a blank channel in between.
- Ex: Ch 61, Ch 63, Ch 65, and Ch 67.
In any case...
It will be hard for anyone to give you an answer since it appears that you do not know what type of receivers you have. Also, a "splitter" and a "diplexer" operate differently, and diplexers operate in pairs or in conjunction with a home node.
EDIT:
If you take another look at your hook-ups to try and figure this out, go to the below link and you will find a lot of info that might make this simple, especially the documents titled "Distribution Examples".
DISH Pro 500 & DISH Pro 500 Plus Information Documents | Solid Signal