Hey! Thanks for getting back to me.
Group 1, file share link is private (not accessible) when pasting URL, file privacy setting = restricted to group. Folder setting = no folder.
Group 2, file share link is public (accessible) when pasting URL, file privacy setting = Privacy of this item rely on its parent folder, Folder setting = restricted to group.
In both cases the privacy setting is set to private. So to answer your question directly, it’s not a folder to folder situation.