No Previous Month link on Calendar view

For some odd reason, on my installation the calendar / view as Month is not displaying the previous month link.

In the HTML generated the Events Sub Nav prints;

<ul class="tribe-events-sub-nav">
	<li class="tribe-events-nav-previous" aria-label="previous month link">
			</li>
	<!-- .tribe-events-nav-previous -->
	<li class="tribe-events-nav-next" aria-label="next month link">
		<a data-month="2017-05" href="https://**/diary/2017-05/" rel="next">May <span>?</span></a>	</li>
	<!-- .tribe-events-nav-next -->
</ul>

So it just seems like the plugin isn’t generating the previous month Anchor.