Alert Composer not getting all records from database

Summary

Alert Composer not getting all records from database, even though using OTBI I get all using the same query

Content

Hi

I have created a simple alert in Alert composer using direct query.

The query is this: 

exists (select 'X' from PER_ALL_ASSIGNMENTS_M where (RETIREMENT_AGE is not null) and (RETIREMENT_DATE is not null)  and person_id = ${PersonId})

The alert is pulling only 8 records from the database. 

However if I run the same query in a data model in Analytics I get 9 records.

(select * from PER_ALL_ASSIGNMENTS_M where (RETIREMENT_AGE is not null) and (RETIREMENT_DATE is not null)  )