This is the mechanism behind almost every complaint about a fast payout that was not fast.
The automated path described above only exists because the operator has already decided it does not need to look at you. Anti money laundering obligations require an operator to identify a customer at certain points, and the trigger is usually cumulative withdrawal volume rather than a single amount, though a first withdrawal to a new address, a mismatch between the deposit and withdrawal method, or an unusual pattern of play can all raise it earlier. Once raised, your withdrawal leaves the automated queue and joins a human one.
The change in scale is the point. The same payout that would have cleared in under a minute is now waiting on a compliance officer reading a document, and operators describe that wait in working days rather than minutes. Working days exclude weekends and public holidays, so a Friday evening request can sit untouched until Monday before anyone opens it.
It gets longer if the documents are rejected. A photograph with glare across the number, a cropped corner, a utility bill older than the window stated in the terms, or a name that does not match the account exactly will send the request back, and the queue starts again from the resubmission rather than from the original request.
The fix is unglamorous and it works. Verify the account before you have a balance worth withdrawing, preferably on the day you register. Use the name on your identity document as the account name from the start. Photograph documents flat, in daylight, with all four corners visible. Then the risk engine has an identified customer to look at and the automated path stays open.
Sites that ask for nothing up front have not removed this step, they have deferred it to the cashier. Our no KYC casinos page sets out what that trade actually involves, and the KYC guide covers what is normally requested.