Good observation. I did have to reboot my Roku a couple of times this weekend. Maybe too much traffic with The Punisher and Longmire coming out at same time.I saw your post & I can offer this insight. I don't have Dish(which means I don't have a Hopper either), but I do have a Roku 3, & I'll occasionally have Netflix do the same thing that you are describing on it. Hearing that it happens on your Hopper too, makes me wonder of it's a Netflix problem.
Edit: I have Comcast & my Roku is connected wirelessly, so it very well could be a connection problem with me. But hearing your problems just sounds like deja vu to me.