Thank you for letting me know. I have sent you an email titled "Shopify Forum Support" so I can verify the account and get this escalated. If you can reply to that email as soon as you're able then we can get the ball rolling on finding a solution.
My developer suggest to follow these steps:
One suggestion I found is going to PayPal and deactivating Shopify from there, then go back to Shopify and try to connect it again: