Some Data not showing up in SSRS Report

I have a report that reports the active records in the table. There are roughly 30K records in the table that the report should generate. It generates data on all the records but a portion, some 400 records are not showing the update that was made to a specific field. When I look at the table in SMSS, the values are there. Again, the records are there, just the updated data from a month a go aren't showing.

Frustrating as I know the data is there. Please help

How is the data being called from ssrs reporting?

Straight sql or stored procedure?
Are you sure the configuration is pointing to the proper server and db?