When inserting message(s) in a folder, the shaded highlight stays with the last selected message but the dotted frame stays at the same relative position in the list as the selected message used to be.  There can be similar behaviour in the list of folders.

The only thing that may seem odd is that if you do a message selection (using shift or control keys), the 'current' position is the dotted highlight, not the selected message.

It may be an artifact of the particular Windows control that is used to display the folders.

Open a folder and you will see the message you last opened highlighted in blue, but the latest highlighted with a dotted frame.  Hit the enter/return key and the blue highlighted one will open, not the one at the top.  Also, hit the up arrow, nothing happens, but hit the down arrow and the message below is now properly highlighted in blue and dotty frame combined and will open properly with the enter key.  This behaviour has persisted for quite some  time.