Audacity doesn’t apply filters, effects or corrections on record and it gets its sound from Windows. So it’s up to you to convince Windows to make a mono mix. Much of the time if you tell Audacity to record Mono and the show is in Stereo, it will just fail.
It’s not just jamming Left and Right together. You also have to reduce each signal by half so the mix doesn’t overload if the same thing appears on both left and right.
I’ve been using audacity for years on other machines. Been recording the same kind of stuff in mono for years with no problem - ever!
New machine and new version of Audacity started this problem. I don’t even get to the point of recording an audio stream when set to mono - just get error code.
Thanks Koz. No offense, but I need a different answer.