*Note: This only applies to legacy portals. Current Publishing Portals will automatically sync library changes to portals.
The folders that are attached to Portals from the main tenant currently do not automatically update when the contents are updated in the Main Library. For example: If a file is added or deleted from a folder in the Main Library and that folder is also in a Portal, the change will not be automatically occur in the Portal.
For changes in the library to be reflected in a Portal, an Administrator must sync the Portal.
To copy content over, Administrators should navigate to the to Settings, and then select the Portals tab, followed by the existing portal you would like to edit. Click on the pencil icon to edit.
Click Sync in the upper right corner by checking on the box.