Commission is earned on completed Experiences. So if a booking is cancelled or refunded before the Experience takes place, no commission is due on it.
Why this is how it works
Your commission is tied to a traveler actually enjoying their Experience — not just booking it. If the Experience doesn't happen, there's no completed booking for commission to be based on.
In practice:
A booking that's cancelled before the Experience — no commission is earned, since the Experience never took place.
A completed Experience that's later refunded — if a completed booking is refunded, the related commission is voided.
What this means for you
Most of the time, this is straightforward: the bookings that complete are the ones you earn on. Cancellations are a normal part of travel, and an occasional cancelled booking simply doesn't convert to commission — it's not a penalty, just the nature of earning on completed Experiences.