The most probable cause is that the new hire is not by default setup to allow accruing of PTO/Sick hours. For an employee to be eligible for accruing PTO/Sick hours, he/she needs to be setup to allow accruing.
A typical sign that employees are not setup correctly is when the Day Off Accrual report shows "N/A" across the row.
To fix this (and check others) go to Preferences > Personnel/Employees, find the employee in the list (do not click on name), then click the "employment" button to the right of their name. On this page, click "edit" then you will see a page with a checkbox option of "Eligible to earn days off." Check that box and submit.