Withdrawals are sometimes cancelled on the casino's side. A request may return to the balance if the payout method has been closed, the bank details contain an error or a bonus condition was still open when it was made. The payment history marks these returns, often with a short code. Support can translate the code into the reason in plain words, and a corrected request usually goes through on the next attempt.
Payment providers go down more often than casinos admit. When a processor has an outage, deposits fail across many sites at once, and withdrawals queue until the service returns. Casinos usually post a notice on the payment page or in the live chat, and the provider's own status page confirms it. Waiting a few hours is normally enough, and switching to another method during an outage can leave two payments to reconcile later.
A casino can place a hold on the account itself. Missing documents, a name that does not match the payment method, or a change of address during play can all pause withdrawals until the details line up. Larger wins or unusual deposit patterns can lead to a source of funds review, which asks for payslips or bank statements. The message about a hold normally names the missing item, and sending exactly that item ends the review sooner.