I understand how they work and figured that was why, and I didn't read all the other posts in this thread, but if you use only 1 HIC does that make a difference? Are you able to hard wire or use Wifi to one Hopper and then enable bridging to share the connection with the other Dish equipment to see if you still have these same symptoms?
Is Dish ever going to enable the second Ethernet port for pass thru purposes? Seems like the hopper already has switching capability, why not add the second port to the mix?