After the first data sync has run successfully, order sync from Magento2 can be deactivated as the sales-tracking from the extension takes over.
To deactivate order sync, go into your Magento2 backend, click on STORES and then CONFIGURATION:
Next, scroll down and find the tap named CLERK, click and press CONFIGURATION:
Click on SYNCHRONIZATION, change the field DISABLE ORDER SYNCHRONIZATION to NO and press SAVE in the top of the page:
The changes take effect immediately.