This is the exact same issue I’m having but for me it’s only happening in the first few channels. It’s only happening with channels 2.1, 2.3 and 2.4 everything else seems to be fine and allows me to select the second signal in that specific channel group.
Following this thread for a future fix.
If it helps:
Tuner: Hauppauge Tuner
Zip Code: 07922
My Thread with details
