Open in new tab from reading list doesn't work as expected

A potential bug if confirmed and I’ve not misunderstood something. My procedure:

  1. Open up the reading list on the left hand window with an unrealated single document, e.g. no additional tabs, already displayed in the central window.
  2. Right click on one of the documents in the reading list and select “Open in New Tab” from the contextual list

Nothing happens. If on the other hand there are already 2 or more tabs in the central window the same procedure above yields a new tab with the content of the reading list item displayed as I expected.

Could you please post a screenshot of Preferences > General and of the main window right before using “Open In New Tab”? Thanks.