I've seen this has been an issue with many hosts..
I was slack about updating default payout when I had a closed bank account so for over 6 months , 20 transfers were sent to my closed account that bounced back from my bank to Airbnb.
I have presented proof of return funds from my bank (though some missing)
When Airbnb payments raised as an issue with the payment processor, then end up sending the proof of original payout. So we simply go in circles and I am asked for proof of returns AGAIN.
Super stressful - I had no money for repairs etc....
It makes me wonder what is going on...are they being deliberately thick. Where is the money?
I believe an internal investigation is needed, as returned funds are being held and not paid out.
My Q is how to escalate it???