One day recently the volume output of my Dual Lite became very low. I do not know why. Today I did a search to see if there was a fix. I did not find one, but one of the posts led me to my solution. I have a Roku 4K Streaming Stick. When you hit the * on the Roku remote, a menu comes up for Captions and Volume. I had mine set to “Leveling”. I changed it to “Off”. Nothing happened, so I hit * again and changed it back to “Leveling”. All of a sudden the volume raised back to normal levels. All good.
In my case, it was turning Leveling off and then back on again that fixed the Tablo volume issue. Sometimes these apps need a “kick”. Once I could not get English subtitles to work on another app. I turned on Spanish subtitles - they worked, then tuned English subtitles back on, they worked after I did that.
As I see it, no app is perfect, you just have to learn how to fix them. The fonts on the Roku Home Screen sometimes get small for no apparent reason. Changing the wallpaper will restore the font size back to normal. A “kick”.