It's nothing Opus is doing. Maybe a false positive, or a shell extension loaded into the Opus process. See if it happens when browsing to a particular folder or viewing a particular type of file, and then try the same thing in Explorer - probably the same thing will happen.
What kind of access? It's probably just responding to change notifications, and checking if the things being changed affect the folder tree or folders that are currently displayed. That can involve testing the file attributes (e.g. to check if something is a file, folder or junction) but shouldn't involve actually reading the file contents.
Maybe you're right. But I checked the windows and folder tree I opened in Opus, just found no one related to the Edge browser. Now I consider it was the Edge browser's problem. Thanks.