How to prevent downloading but allow editing files and folders in Microsoft Teams (SharePoint)

Question

Microsoft Teams has automatically a Guests group to users outside of the organization. I'm looking for a solution where folder with Word and Excel files are for online editing but not right to download those files and folders and subfolders. This should concern Guests (Visitors group), users in that group.

Even the Visitors group has not permission to the folder, Guests can see and download the folder. There is an overriding permission for Visitors?

The restricted folder is inside the Teams General folder or in the same folder of General, not difference. In SharePoint I have activated SharePoint Server Enterprise Site Collection features on both site and site collection. New permission level copied from View Only and added Add Items and Edit Items and then Stop Inheriting Permissions for folder, removed old Visitors group (Guests) and granted permission back to Visitors group with that new permission level.

Would anyone have any idea how to allow editing but block downloading?

Answer 1

Here are another two ways to block downloading.

1.Apply a block download policy to a SharePoint Online site. This policy affects all users.

https://learn.microsoft.com/en-us/sharepoint/block-download-from-sites

2.Use conditional policy.

https://learn.microsoft.com/en-us/answers/questions/1274429/how-to-enable-block-download-policy-in-office-365