In this case, the issue is simply that some System Filters are activated. System Filters can be toggled by using the Toggle Sidebar icon, located in the top bar.

Most of the screens have this icon, including Employees, Leave and Payrolls screens.

Once clicked, you can choose from the side which System Filter you would like to toggle. Click on Active this Year to disable this particular filter.

Read more about system filters and how you can locate historical data with them in this article.