I have tried this exactly and the program will not let me turn off the auto payroll feature for an employee
Turn off Auto Payroll
If you wish to stop paying one or more of your employees via Auto Payroll, you need to unenroll them.
Make sure you're signed in to QuickBooks Online as the primary admin.
Select Settings β, then Payroll settings.
In the Auto Payroll box, select Edit β.
Select Select employees for Auto Payroll.
Select one or more of the enrolled employees.
Select Save changes.
Review the confirmation window, then select Done.