Before you get started
If the approval process is automatic when there are no variable items, and a timesheet with no apparent overtime has not been automatically approved, check the points below.
A timesheet without overtime was not automatically approved
Check the approval process settings in Settings > Approval process. If the process only requires approval for counted variable items and a timesheet with no visible variable items has not been automatically approved, this means that the time has been posted to non-visible time accounts.
Go to Settings > Time accounts to see if there are any time accounts that are not visible:
Then check in Reports > Account report whether hours have been posted to these accounts for this timesheet.