Your effort in fixing the issue you're experiencing with Amazon in QuickBooks Online (QBO) is valued, Ben. I understand that accurate and up-to-date financial records are essential to your business process.
While I wish to provide an immediate solution, this particular scenario requires specialized attention from our live support team. Therefore, I strongly suggest contacting the live support again. This time, specifically mention and ask about the Amazon integration and explain that this is an ongoing issue on your end. To ensure timely assistance, check out their hours of availability in this resource: Get help with QuickBooks products and services.
Should you need any further assistance, please don't hesitate to comment below.