When you share a folder that has many items that have unique permissions and you select the Share all items within this folder even items with unique permissions option, the sharing process seems to complete but never makes changes to the items' permissions.
There is limitation of 500 unique permissions for each sharing request. If the folder that you are sharing contains more than 500 unique permissions, the sharing process will not apply the changes to any items.
To work around this issue, use these methods:
- Separate content into multiple folders or libraries to avoid the 500-item limit for unique permissions.
- Share sub folders instead of the top level folder to avoid the 500-item limit for unique permissions.