When you copy & paste a link into VisualEditor, it will not be recognized as a URL, but will appear as plaintext. The MediaWiki parser does render it as a clickable link, of course.
This is annoying especially for references, because you might be confused why your link you're adding as a citation doesn't appear to be clickable.
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=52204