Some general guidelines for sync:
• Use a shared "master clock". In this case, that would mean to use the exact same expression (or PulseTrain) for all Sounds. If they are at multiple or submultiples of each other, it is more accurate to use the form:
1 bpm: !BPM triggerEvery: <Multiple>
than it is to use (1 bpm: !BPM / <Multiple>)
• Enter the clock expression directly in the parameter field that depends on it, not via a SoundToGlobalController
• If you run into a situation where the clocks seem to be drifting over a long period of time, send a periodic resync to the Sounds.
Suspect that the issue in this particular case is that the Chopper does not have a Trigger field so it can't take the exact same expression as the Oscillators and Samples have.