Check which guide view is active
A channel absent from a favourites-only view is different from a channel the tuner cannot receive. Likewise, a hidden guide source can make many channels disappear together. Before rebuilding a DVR, note the guide view, selected sources and whether the missing channel appears when browsing the complete relevant source.
Use the documented guide controls
Plex’s guide documentation says big-screen apps can mark channels as favourites, reorder those favourites and enable or disable live-TV sources in the guide. Sources can include multiple DVRs and the free streaming service. The latter controls are available through the guide’s additional menu. These choices organise the displayed schedule; they should not be described as changing antenna reception or supplying another subscription.
Review a mixed-source household example
Suppose a family combines its own tuner with free internet channels but wants a short list of frequently watched stations. Favourites can serve that purpose without removing the other source from the system. If a whole group later seems missing, inspect the source filter before rescanning the antenna. Check a known channel after the deliberate view change and retain the distinction between “hidden in this view” and “cannot tune”. Record the app and selected guide source when requesting help. This makes it easier to diagnose a presentation setting without disturbing an established recording configuration.
Questions, answered
Does disabling a source in the guide prove its reception failed?
No. Plex documents that control as guide-source visibility.