Expression Engine 3 - Entries Tag - page_uri empty

I’m rewriting my question in order to explain everything properly, so here goes.

We were using ExpressionEngine 3.1.0, and have recently updated to 3.1.2 - pretty much as soon as it was available to do so.

Since doing so we’ve run into a genuine error with the {page_uri} or {page_url} tag. The pages module is installed and we’ve added a news item that utilises it. All fields required are filled in, so there is no error there.

The problem we are getting is that absolutely no content is being output in the {page_uri} or {page_url} tags and cannot find a reason for it. Our loop, including testing code, is below:

{exp:channel:entries channel="news" limit="1" dynamic="no"}
 (1){url_title_path='news'}(2){page_uri}(3){page_url}(4){permalink}
 <div class="item-double news">
  <div class="social-wall-logo">/assets/local/img/news_icon.png</div>
  <div class="social-wall-heading">News</div>
  <div class="social-wall-content">{title}</div>
  <div class="social-wall-view-more"><a href="http://{url_title_path=news}{page_uri}{page_url}">/assets/local/img/view_btn.png</a></div>
 </div>
{/exp:channel:entries}

The channel is correct, {url_title_path} does output the title but this isn’t the correct way of outputting URIs and all other tags (like {title}) output what we’ve entered.

We’ve spent about 2 hours on this bug and cannot think of nor find anything that we’ve done wrong. But if you can see something that looks amiss please, please say so, haha!

Thank you for looking,

Andy