eBay selling using pay pall credit

Description

I am in the UK and have sold an item on eBay to someone in the USA using the eBay global shipping programme. I cannot send an invoice to the buyer, and he wants to pay using paypall credit. I have googled this and it looks like I have no option but to accept this, which is fine with me, however now the buyer says he cannot proceed with the transaction. is it my end or the buyers end in the USA at fault? how to I rectify this problem so I can receive payment and post the item. due to the coronavirus no one at payPall is available to contact? any suggestions please?