This may be an obvious question, but have any of you who are having problems with Alexa tried unplugging your Echo Dot (or whatever Alexa device you are using) for about a minute, and then plugging it back in? Earlier this week, I was having audio dropout issues with anything I tried to play on my Echo Dot. I unplugged it and plugged it back in, and that fixed the sound problems for me. I still have issues with the Live X Live skill, where it will either suddenly stop playing for no apparent reason, or the skill will stop working entirely, making me have to Disable and then Enable the skill again to get it to work again. These issues seem to be specific to just that one skill, though.
Having said that, I gave up on having my Echo Dot control any of my Dish receivers a long time ago. At first, it worked great. It was paired with one specific Wally, and I could control that Wally without having to specify a room name or even say "...on Dish" most of the time. Then, something got screwed up, and I would have to specify a room name, or it would suddenly switch to controlling the wrong receiver for no apparent reason. It finally got to the point where it would not work for controlling any of my Dish receivers anymore, no matter what version of the command I tried. I think part of the issue in my case was that I had too many receivers on my account, some of which had the same room name as each other. ("Living Room 1" for both the Wally and the Hopper Duo in the Living Room, for instance.) I have since sold all of my old Wally and Hopper Duo receivers. When I get the money and time to finally purchase and install a Hopper 3, I may try to pair Alexa to that receiver, and see if it will start working, with none of my other old receivers on the account to confuse it.