Contour and Android 11 Incompatibility?

With Android 10, up through yesterday, Contour worked fine. A selected show ran as expected. Google encouraged an update to Android 11, which I dutifully installed last night. Contour now works up to the point of viewing the TV channel, but with only a black screen and no sound. If the screen is then tapped, a "run" button is presented, along with a miniature circle in the lower-left corner. Clicking the run button results in a pause button. Clicking the pause then causes the run button to be quickly displayed, reverting to a pause button immediately. I removed the Cox app and the Cox Contour app, reinstalling both. I did that twice. No change--clicking on a particular show/movie/live broadcast results in a black screen. The phone is a Pixel 2XL. No prior problems accessing Cox Cable via Contour. I checked Contour on my laptop, and it presented programs just fine.

I just did. It only had a couple hundred kB in it.  Same for the Cox app.  No change--black screen.