What is historical checks appeared in payroll summury?

Welcome to QuickBooks Community, villareya. Allow me to help you understand why historical checks appear in the Payroll Summary report in QuickBooks Online (QBO).

Before we proceed, may I ask if you have transferred your payroll data from another software to QuickBooks Online Payroll? If yes, that's the reason why you're seeing historical checks posted in the Payroll Summary report. This occurs when you have previous payroll transactions that were entered outside of QBO before your migration. These checks are part of the payment records you made from earlier periods.

After the migration, you won't see the breakdown of those historical checks in the paycheck lists. Historical checks processed outside of QuickBooks Online (QBO) will only be visible in the Payroll Summary report. You'll need to access your previous payroll service for a comprehensive detail.

However, if you've not migrated from any other program, you can run the Payroll History report to view the details of each check recorded inside QuickBooks. From the Reports menu, search for Payroll History. 

You can read this article for more details about generating reports in QuickBooks: Run payroll reports in QuickBooks Online Payroll. 

I'll be around if you need help managing paychecks or any payroll concerns in QuickBooks Online. Bye for now and stay safe.