Secure Folder is a secure space, so data and apps are completely separate from those outside Secure Folder.
Your app data does not move inside Secure Folder when it is re-installed. You will need to configure the app after moving it to Secure Folder before you start using it.
Take advantage of data separation to create separate accounts for your Secure Folder apps.
See the Secure Folder User guide for more information on using Secure Folder.