I got an email this morning from the tech team. They checked my Hopper logs, and found no issues. They tried to duplicate the issue at their location, and they could not.
They are continuing to investigate.
What would be helpful, is if other members confirm YES or NO to the following.
Using a Hopper 3, with NO PLUS!!
Watch a 4K Event with Dolby Sound "ON" in the Dish Menu
Connected to Dolby capable Sound Bar or AV system
If you get no sound -
Respond YES
If your sound works as expected
Respond NO.
(Note that sound will work with Dolby sound switched OFF.)