I am having the exact same problem. I have to reset the entire Hopper3 to regain 4K Netflix.
You said " After I restore the app from within the Settings on the Hopper 3 I am able to receive UHD programming."
Since it appears a fix from Dish is not coming soon, can you explain how to restore just the Netflix app? Thanks.
To restore the Netflix App to factory defaults, press the Menu button twice on your remote to get to the Diagnostics screen, then go to "Tools" on the left side of the screen. Select "Reset to Factory Defaults" and it will have the option to reset the Netflix App to Factory Defaults.
If you don't have a Menu button on your remote, press the Home button on your remote 3 times to get to the Diagnostics screen.
I apprectiate the response since Dish chat said unpluging the Hopper3 was the only workaround and that tech people were unaware of a problem.
After resetting Netflix one has to sign-in again which would be simplier if the option to remember my Email worked.
It seems accessing Netflix directly from my smart TV and ignoring Dish is the best answer for the forseeable future.