If you are using a VPN/SOCKS proxy/ or Tor, your transaction will be blocked by out fraud controls. You must use a real residential IP and ideally one that is near the address where the card is registered to.
The whole anti KYC talk goes pretty much down the toilet. You aren't asking for identity documents from your customers, but you do need their names and card details and real IP addresses.
What could be some reasons your fraud department could flag a transaction?
What happens if I deposit coins from a mixer?
What happens if they get deposited from a crypto casino?
What happens if the person who sold me the coins got them in an illegal way and now you are flagging my transaction?
Do you consider some bitcoins to be "dirty" or "tainted", or are they all the same?