Hi, I am happy for you to ask the question but please do so before awarding. If I know the answer or can find the answer then I will accept.
I am online generally office hours from HK time, but if I am not online I will reply as soon as I can with a yes/no as to whether I can help or not.
I see that you mentioned it's not an API issue but let me say please that I have taken payments from Paypal for nine years, averaging around 100-200 payments per month (mostly API but some direct payments too) and I use paypal as a customer quite a bit too.
Thanks, and good luck!