Did you do anything special with the M1 MacBook Pro? I updated my iMac-M3 and the DVR can't find any channels on my HDHomerun tuner - The error message is " No channels detected on this HDHomeRun. Please scan for channels," The channels are there as I can see them with my raspberry pi DVR, and VLC...
Please see the suggestion made in the other thread you posted on, as this is a thread about the Channels app, not Channels DVR Server.