I donīt know if it is a bug or if it should just be made clear in the manual:
I changed the MIDI-input for "Track 1" to "OFF", "Drums" remained set to "10".
Although I ran track 1 in sequencer mode, it still recorded notes received on channel 10 until I turned the drumsī MIDI-input to "OFF" as well.
At least for me the separate channels in the utility menu let you expect that it would listen to either one of the channels depending on the trackīs mode.