Hi LaurensPP, 

It's best to contact our QuickBooks Technical Support Team to have this checked further and investigate the root cause of this issue. They have more tools to help you export your QuickBooks Online (QBO) data to QuickBooks Desktop.

You can follow the steps to contact our support team.

I'd be glad to share this link if you'd like to try QuickBooks Desktop and download a free 30-day trial: Download a trial of QuickBooks Desktop.

Let us know if you have any other concerns. We'll be around to help.