Hi Jennifer,
If you make an update to the case property configuration this will not be applied retroactively to previously submitted forms. That is, if you had two cases, one created before your update and another one created after your update then your new case properties will only have values for the second case.
If necessary you can use the Excel Import tool to update your previously updated/created cases with the new case properties.
Also - you will need to deploy the latest version of the app in order for the case property updates to take effect for new cases.
Jeremy