Thanks for following on this thread, @ 20fec.

Based on the information provided, manually change the classes each time you run payroll. This way, QuickBooks Online will be able to properly classify your employees. 

I have a few easy steps to accomplish this task. Here’s how:

1. Go to the Gear icon at the top and choose Payroll Settings under Your Company. 
2. This will open the Preferences page.
3. From there, navigate to the Company and Account section and then click the Accounting link. 
   
   
4. On the Accounting Preferences page, go to the Classes section and mark the radio button for I use different classes for different employees.
   
   
5. Hit the OK button to access the Preferences-Employee Classes page.
   
   
6. Select the appropriate class associated with your workers.
7. Once done, press OK to keep the changes. 

To learn more about the Class feature, check out the Get started with class tracking in QuickBooks Online article. It provides an overview of how to set up a class list as well as instructions to create a budget by category.

Let me know if you have any other concerns or questions about the product. I’m more than happy to assist further. Enjoy the rest of the day.