This anomaly applies to IC Rev. Engineering B, build codes QFAA-BA0, CHAA-AA0.
RCOSC only calibrates on every second calibration request.
Always
RCOSC not properly calibrated.
Trigger TASKS_CAL, wait for EVENTS_DONE. Trigger TASKS_CAL again, wait for EVENTS_DONE each time the RCOSC is to be calibrated.