When I create a shipping build, 3rd Party DLL doesn't read or write to the plugin directory

Here’s my package directory structure:

WindowsNoEditor / [projectName] / Plugins /

C# creates directories and files under the Plugin folder. It also reads from the same directory. When I do a shipping build, the directory remains empty after running the game, and the game fails to read data from files in the directory.

When I package the project for development build, everything works. Is there something I need to be aware of?

Does the shipping build not allow C# any file access inside the package? I have DLLs inside the plugin folder that reads/writes files. How does this need to be configured?

UPDATE: I modified C# to read and write from a custom user directory but that still doesn’t allow the DLL to read or write to the file.