@mib2berlin The default is Bookmarks:
38feb00e-2f02-494e-a8e9-31e1832247e4-image.png
Note that this is not the same as "Bookmarks" shown in this image, which is just a folder. This is the Root folder.
Once changed, it cannot be set back to the Root without doing the above.
See VB-83735 - which is not actually 100% fixed since the Boomarks root entry is gone once changed.
Make sense?