Groove Quantise Only Works with Groove Clipping Disabled on Source/Target Clips?

Apologies up front if this is a bit of a lame question:
 
I dragged some 6/8 MIDI drum loops from the browser into the arrangement and got a really nice little syncopated rhythm going with an electro bass line, also sourced from dragging MIDI from the browser. To make the parts groove together even better I copied the MIDI drum clips (all six in a sequential row) to the clipboard and tried to Groove Quantise the bassline to follow the dynamics and timing of the drums. This had no effect until I disabled groove clip looping on both the source and target MIDI.
Both instrumental parts were playing from one instance of Kontakt 5 on separate MIDI channels.
 
I can't recall ever having to take these additional steps before i.e. should you have to disable groove clip looping on MIDI to apply groove quantise?