"A new router doesn't mean it is working right or set up right"
Isn't that a true statement.
So many things will affect a wireless connection.
QoS settings that allow transmission bias based on what is connected to the system at any given second..
Frequency load balancing between the 2.4 GHZ and one or more 5 GHZ channels
Router positioning and antenna "aim".
Soooo many non ISP related potential items on the checklist.
"He checked your router or just the HughesNet equipment?"
I would think just the Hughes stuff if on the Hughes "dime". Network support for only the Hughes provided D-Link router.
Any "side deals" with the installer are going to be a crap shoot depending on the knowledge and experience of the subcontracted tech.
At times Networking can be just as much Art as Science.
Much time can be spent in tracking down wireless issues.
I had a 900 MHZ cordless phone that was starting to fail in some manner. The phone worked great but it really had a bad effect on my 2.4 GHZ wireless performance.