I have Channels v5.1.0 on an Apple TV tvOS 15.1.1 with a DVR and two HDHR devices - HDFX-4K and HDHR5-4K
Some channels have 2 sources so they probably appear 4 times and do not get deduplicated.
The puzzling thing is 2.1 and 2.2 are fine while 2.3 and 2.4 are duplicated.
The DVR server deduplicates everything properly.