Firstly, you need to ensure the leave suspension in Access EasyPay has been set based on the probation duration or not. If not, please update it accordingly as follows:
Go to the Leave module, Setup, and click Leave Type.
Select the Leave Type and click Suspend.
Ensure the setting tick to User Defined - Suspension starts from hire date for "3" months and click Save.
Secondly, please check the settings under ePortal, whether you allow your probation staff to apply for leave or not. Below are the steps:
Log in to the ePortal as Administrator.
Go to Settings, eLeave Settings, Configuration.
Untick the leave type beside Allow leave application during probation.
Click the Submit button to save the setting.