Hey Björn,
You are correct, I dont see any option to disable program changes on just the drum track by itself.
Are these imported MIDI files, or a BIAB created song ?

If your importing from a MIDI file, there is an option to ignore all program changes when importing MIDI files, then you can assign MIDI program #'s in BIAB.

Also have you tried clicking on the drum track in the mixer, and from the popup menu selecting a GM patch # that corresponds to the drum kit you want in SampleTank ?

Hopefully this helps.

- Jay

MacPro 5,1/12 core@3.46GHz -- OS X 10.15.7 -- ATI 7970 -- 32 Gig RAM -- Crucial 500GB OS SSD -- Samsung EVO 1TB Audio/Sample SSD -- BIAB 2024 -- Logic Pro X -- Cubase Elements 14 -- Too many plugins