Accessing network drive mounted into assets folder

I am running a dash app on a self hosted server. Within the app, links are generated dynamically trying to access files from a mounted network drive. The network drive is mounted in the assets folder as a sub-directory. When I run my scripts locally on the machine I can access the files without any problem, but within shiny I can’t browse the mounted drive, while I can access other folders and files in the assets folder. File and folder access rights are set to 775.

Structure of the app:
|-appfolder (containing the main app)
|---- apps (containing other pages of the app)
|---- assets (containing some images and data directories)
|----- mounted_drive (the mounting point of the network drive that can’t be accessed)

I checked with os.walk and glob.glob as well and couldn’t get a listing of the files or folders within the mounted_drive directory.
Using a http link as it is possible for all other files and folders in the assets directory doesn’t work either.

Any hints or help are very much appreciated.