"Honouring fee" charged for an instant payment made directly after depositing CASH at an ATM

On the 17/06/2021 I made an ATM deposit. The funds were immediately available and since these funds were available, I made a payment, straight after depositing the cash. Due to the antiquated manner in which your ATM deposits are processed, you allowed the Payment (Money App Payment made as an "instant" payment). Then on the 18/06/2021, you charged me an "Honouring fee". What exactly did you honour??? I made a cash deposit; you made the funds immediately available; I made a payment using the available funds; your antiquated system caused my account to become overdrawn and so you honoured a Mobile Banking Payment? Since when is that allowed? You do not allowed for instant payments against insufficient funds so you didn't actually honour anything. Reverse that fee please.