I tried Channels a long time ago when it was more like TV Everywhere with DVR features, but it was officially threatening to become a cloud-based service rather than a local PVR setup. Much has changed since then, and apparently not all for the better.
I run Plex (with a $40 lifetime PlexPass subscription) on a Debian-based mid-tower server (my daily driver before I switched from Windows XP to Debian 9 on an even older machine). It has been 100% stable with my HDHomeRun tuner, and Plex device support is broad. Originally, I was running Ubuntu, but I'm feeling much better now with Debian 13.
If Channels is that fussy, I can't imagine using it, regardless of how hard it tries to cover its backside -- especially when used with an OTA tuner where there are no second chances.