Why don’t all payslips appear in the sheet?

The sheet shows the payslips you’re allowed to see based on your permissions and the filters:

Permission	Payslips shown
Manage Payroll Settings or account owner	All payslips.
View Pay Run	Payslips of the branches you’re allowed to access.
View His Department Payslips	Payslips of your department’s employees.
View His Own Payslip	Only your own approved or paid payslips.

If you open the sheet from the payslips list, the list filters are applied to it, so review the filters.