I have a schedule section. That is also where I find the shows that indicate they are to be recorded. When I select any of these already recorded ones in the schedule section and choose to cancel recording them, it does not affect the schedule. However, if I go to the trash and delete the trash, all the items I have watched, that were deleted, as well as the ones I asked to be removed from the schedule, are now gone from the schedule list.
That means I no longer see the ones that were already watched or scheduled (these latter ones represent the duplicates that somehow got introduced again into the schedule, and on the very same day that I'd already scheduled and watched them). Seems there's some sort of synchronization problem going on.
As for the app, it is running on my Apple TV with the server on the Synology. I never turn off the Apple TV. My setup uses a combination of a Google Nest Mini and Harmony Hub and remote to engage my projector, video processor, and audio processor. So, I guess the app will run either in the Apple TV's foreground or background. Unfortunately, the Harmony seems incapable of turning the Apple TV on or off, so I simply leave it on, rather than using its remote. When I start the activity to watch the Apple TV it brings up the start screen with Channels DVR as one of the app options, including my HDHomerun.
Hope that helps...