I clicked "Show in Files" and it opened the directory. After a while, I re-visit that directory, and thought I had already opened it in Files, but there was no instance of Files (no "running" green dot), so I thought I had closed the directory, and clicked "Show in Files" again.
Later I found that there were lots of duplicate Files windows for that directory, but there were all grouped with Rider, not with the Files. As you see in the screenshot below, the Files app (first icon) shows no instances, as if it is not running, and Rider hows two blue dots, but there is only one Rider and the other is just the Files window.
Is this an intentional behaviour or bug? If intentional, can I make the directory window treated as an instance of Files, not Rider?