Chord Track Records Notes From Non-Specified MIDI Track

I have the Chord Track set up to listen to a particular MIDI track. But it is also picking up input from another, non-specified MIDI track.

This only happens when I am holding down notes that are routed to the specified MIDI track. In this situation, notes for the other track modify the held chord. For example, if I am holding an Fmaj chord with my left hand and then I hit an E with my right hand, the Chord Track records an Fmaj7 at that point in time.

Have I run into a bug in Cubase, or is this something that I can fix?

Thanks…

Cubase Pro 13.0.20
Windows 10