HR Specialist with custom person security profile can't see all terminated workers

Summary:

HR Specialists with a custom role that prevents them seeing HR peers can no longer see all leavers. They can see most leavers but there seems to be a pattern where they cannot see leavers that were recently hired and then left within a short period of time. I have updated the Custom Security Profile but still some leavers are not visible.

Content (please ensure you mask any confidential information):

The custom security profile is below. Can anyone offer any advice on what may be causing the leavers to not display please?

(EXISTS
(SELECT 1 FROM PER_ALL_ASSIGNMENTS_M ASG,PER_PERIODS_OF_SERVICE PS