thanks for the hint about the driver. It appears HDHomeRun does not like vsync=fast, which I have set (among others). It works if I use any other vsync option (off or on) or if I set "use application default" in nvidia settings.

some of the channels stopped working on windows 11. I live in Madison, WI, and all of the lower channels, main sub-channels are not working: 3.1, 15.1, 21.1. When I switch to them the application hangs and I have to click x to close it. The minor sub-channels (3.2, 15.3, etc.) and other channels (27 ...