24 quantity minimum small and light

Hi guys

So when we first started selling on Amazon last year, we read that for small and light items, you cannot ship less than 24 items per shipment to the fulfilment centre.

However we accidentally generated a box with less in a little while ago, and didn’t come up with any errors.

Is the rule of 24 still active? Should it have generated an error? Or does this not apply anymore?