Hi Theuns,
If you're a new host, Airbnb may hold your payouts for 30 days after your first reservation is confirmed. If your first reservation is more than 30 days away, your payout will be released 24 hours after your guest's scheduled check-in. This will apply to any payouts scheduled to be released during those 30 days.
Please check out this article: https://www.airbnb.com/help/article/425/when-will-i-get-my-payout
In some occasions, Airbnb need hosts to upload a government ID in order to receive your payouts. If this is the case, you should have received an email with information.
If you believe that your payout should have been sent 24 hours after check-in, or the 30 days' period has passed, then something may be wrong and you best call Airbnb for clarification.