[Users] highlighted message in list pane does not open/appear in message viewing pane until I click on it

[bqt]

When I am reading my new messages, and I delete one from the list pane,
the next message down "moves up" so to speak and is highlighted (blue
background, white text.) Which is fine and expected. But the text of
that now-highlighted message does not appear in the viewing pane below;
doesn't "open up" so to speak. Is that the designed behavior? Is there
a setting I can change to make the contents of whatever message is
highlighted/selected in the list pane appear in the reading pane?

Thanks.