The fewer the tracks the more accurate the chord detection. As Bob indicated lead lines as well as any moving parts can confuse it. I would separate the tracks and find the most basic rhythm track, usually it is either a piano or guitar part. Sometimes you will need to include the bass line if it is playing the tonic of the chord. Bring those two tracks into RB/BiaB to determine the chords. YMMV

Whenever I get something stuck in the back of my throat, I dislodge it by drinking a beer.
It's called the Heineken Maneuver.

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware