Sirius app turns off the roku box after a few seconds when listening after I turn the TV off

I like to listen to Sirius radio app with the TV off.  In the last few weeks, when I open the Sirius app, start playing music and then turn the TV off, the music plays for several seconds then it stops. The LED on the ROKU Ultra box turns off, and then comes on after a few seconds, like the power is being cycled??  In the past, when I turned off the TV, the music would stop for a couple of seconds, then start playing again.  It no longer starts playing again.

I can only listen to music if the TV is left on.  I have the Ultra box feeding a Yamaha AV receiver that is several years old, i.e. not updates to it.  The only thing that has changed is the software revision for the Roku Ultra box.  I did download the latest update, and the music stayed on for a few minutes, then did the same thing.