MIDI input while concert pitch is on results in tpc corruption

To reproduce:
Bb Clarinet score, disable Concert Pitch.
input a C via MIDI.
C is displayed as a C, but sounds as a concert pitch C (expected behaviour: Displayed as a C but sounds as a concert pitch Bb, or alternatively displayed as a D and sounds as a concert pitch C).
If I turn on concert pitch now, then:
the note is displayed as a Bb, but sounds as a concert pitch C still! (expected behaviour: sounds/plays as a concert Bb or a C, respectively with above behaviour).

I'm about to raise a PR that addresses this but would definitely appreciate someone looking over it with a careful eye to see if I've missed/mucked something else up.