"You can request delegation for these employees" configuration is set to IsInActive=0 however still able to delegate approvals to these inactive employees

Hi,

I want to have all inactive employees as much wiped from the web portal as possible, especially for delegation. Currently can still search in the web portal and find all inactive employees which would like to also remove and keep it just in the One Identity Manager. 

As far as I know IsInActive in the Employees configurable should achieve this, what am I missing or additional settings need to be set? 

Cheers