I have this problem on both my new H3 and 4K Joey. The workarounds that have been posted on here previously worked on my HWS and Joey 1.0 (after the UI Update in June - which initiated this infuriating behavior). However, they do NOT work any more on my new H3 and 4K Joey.
When I attempt to use the workarounds now on the "new" hardware, the video does change to full screen - but playback stops or skips ahead and then it almost immediately locks up the device that the workaround was attempted on. I then have to either reboot the Joey or the Hopper to be able to use them again. I can no longer access my DLNA server (which is hosted on a QNAP NAS) on any of my DISH equipment.
The most frustrating aspect for me is that it worked nearly flawlessly on my "old" hardware prior to the UI Update, and using the Home Media option was extremely convenient - when it worked as intended.
Hopper 3 / 4K Joey