Lightroom Classic: Multiple drives/folders shown at import

I updated Lightroom Classic (MacOS) to 9.0. I'm running MacOS Catalina 10.15.
I don't exactly know when it happened, but at some point, LR Classic started to show multiple drives in the import window. I only have one drive on my Macbook Air ("Macintosh HD") and up to a certain point, it has shown only this one. Now it shows three (3) versions of the drive - the first two are very similar in content, the third one is empty (I cannot expand it by clicking on the triangle button).

Is this a known bug?