Sometimes, you need to stop a folder from being displayed on the sales frontend completely. A great way to do this is by deactivating the folder and then locking it.
In the setup screen within the admin portal, find the folder you want to deactivate.
Then, right-click and select properties.
Then select the status tab and using the tick boxes, deselect "Active" and select "Locked"
Once you have done this, make sure you clear the cache on the sales portal of your Monad system.