Why the configured Employee Rule Setup for a staff is not working as expected?

Why the configured Employee Rule Setup for a staff is not working as expected?

Symptoms:
Leave Administrator configured an Employee Rule Setup for a staff to use a specific Leave Type Rule for leave application. However, system follows the rule for Annual Leave Rule type instead of the newly created Employee Rule setup,

Possible cause (s):
At Leave Type Rule, the Annual Leave is set to One Tier - Immediate Manager with Priority set as "Highest". When set as "Highest", Annual Leave Rule will override employee's rule.

Suggested workaround/ solution(s):
1. Go to Leave > E-Leave Options > Leave Type Rule > click Annual Leave
2. At Rule Priority, change "Highest" to "Normal" and Save.