As this is just a query if this is correct for your school when you upload the Census on Collect you can annotate the reason for this.
To check this information go to Reporting > Reports > Students tab > Free School Meals.
Select year 1 from the group drop down menu and click choose. This will list all students who are currently eligible for free school meals along with the free school meal period start date.
You can edit free school meal eligibility in bulk in Admin > Students > Manage FSM.