I noticed with consternation that when I use the function ‘Copy link’ + ‘People with existing access’ it breaks the inheritance of the security of the file.
My explanation would be that by default when I choose ‘Copy link’, the choice ‘People in your organization’ is activated and the link is automatically copied. The permission inheritance is broken at that moment. Which means that even when I change the option to ‘People with existing access’ the inheritance stays broken.
The way to activate ‘People with existing access’ by default when copying a link is to change:
SharePoint Administration > Sharing > File and folder links > Change from ‘Anyone with the link’ to ‘Specific people’.
Here is a summary of how the ‘File and folder links’ options as shown above affect ‘Share’ and ‘Copy link’. Note that visitors get different choices presented compared to those presented to owners or members.
UPDATE JANUARY 2020: Per-Site Sharing Links can now default to people with existing access. (Featured ID: 60335)
Set-SPOSite -identity https://YourTenant.sharepoint.com/sites/YourSite -DefaultLinkToExistingAccess 1
Set SharePoint Online default sharing link to People With Existing Access