AKOscillatorBank glitches when playing different velocities - audiokit

Question

I'm working on something that creates floating objects then plays notes when they collide. The velocity is worked out then plays a note using AKOscillatorBank play notes. When multiple notes with different velocities are sent, AKOscillatorBank starts clicking and volumes start jumping all over the place. It's like the velocity for any given note affects the volume for the whole oscillator bank.
Works fine when every note has the same velocity. Tried to use a new AKOsillator for every object instead of AKOSillatorBank but that creates its own set of problems.
oscBank = AKOscillatorBank(waveform: AKTable(.sine), attackDuration: 0.01, decayDuration: 0.4, sustainLevel: 0, releaseDuration: 0.4, pitchBend: 0, vibratoDepth: 0, vibratoRate: 0)
// each object has a playNote function that calculate velocity of object then converts to midi velocity value.
//Works fine when velocity is set to a static number eg: oscBank.play(noteNumber: midiNote, velocity: 100)
func playNote (_ velocity: CGFloat) {
oscBank.play(noteNumber: midiNote, velocity: phyVelToMidiVel(velocity))
_ = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: false) { timer in
self.oscBank.stop(noteNumber: self.midiNote)
timer.invalidate()
}
}
func phyVelToMidiVel (_ phyVel: CGFloat) -> MIDIVelocity {
var midiVel = (127 / resizeConstant) * phyVel
if midiVel > 127 {
midiVel = 127
}
return UInt8(midiVel)
}
Loads of clicking when AKOsillatorBank is being sent multiple notes with different velocities.