Hi @ann.lund,
This would happen if you manually generated a pay run, and didn't use the hours listed in your timesheets.
I'd suggest importing your timesheets when you do a pay run so your employee's hours are accurate. This option is available at the start of the pay run.
You may find this list of articles helpful: Payroll for QuickBooks Online.
Reply with a comment below if you have any other questions.