In the post timeline page, we can click a event's permalink to change the currently selected post.
However, clicking another permalink does not deselect the previous selected event, and the highlighted border remains displayed on multiple events.
This makes it difficult to tell which event is currently selected, so it is unclear which event will get shared when the URL is copied from the browser's address bar.
I'm sure this is an unintentional bug, as the post timeline design has been changed recently, and the class that is toggled is now
border-highlight, but the class that displays the highlighted border is
Win 10, Chrome v80.0.3987.122 (Official Build) (64-bit)
Also, please take a look into the top and right border of the highlighted event cell, which should remain plain or unbordered (as per previous design).