Tags not displaying in blog posts since upgrade to 3

Hi,

I just noticed that two blog posts I wrote after upgrading to Runway 3 aren't displaying any tags, on either the listing page or the indivdual post page.

Posts previous to the upgrade are fine.

The posts have tags under the "Meta and Social" tab, and using <perch:showall /> in the template shows the tags under postTags.

One thing I have noticed, the two posts don't have any entries in the perch_blog_posts_to_tags table.

Any ideas what might be going wrong?

Template to render tags

<perch:before>
<h3>Tags</h3>
<ul>
</perch:before>
    <li><a href="/tag/<perch:blog id="tagSlug" />" rel="tag"><perch:blog id="tagTitle" /></a></li>
<perch:after></ul></perch:after>

Diagnostics

    Perch Runway: 3.0.8, PHP: 7.1.8, MySQL: mysqlnd 5.0.12-dev - 20150407 - $Id: b396954eeb2d1d9ed7902b8bae237b287f21ad9e $, with PDO
    Server OS: Darwin, fpm-fcgi
    Installed apps: content (3.0.8), assets (3.0.8), categories (3.0.8), perch_blog (5.6.1)
    App runtimes: <?php $apps_list = [ 'perch_blog', ];
    PERCH_LOGINPATH: /mind
    PERCH_PATH: /Users/garrettc/sandbox/polytechnic.co.uk/htdocs/mind
    PERCH_CORE: /Users/garrettc/sandbox/polytechnic.co.uk/htdocs/mind/core
    PERCH_RESFILEPATH: /Users/garrettc/sandbox/polytechnic.co.uk/htdocs/mind/resources
    Image manipulation: GD
    PHP limits: Max upload 128M, Max POST 128M, Memory: 128M, Total max file upload: 128M
    F1: 0c66c2e1f82f9e0b7617b2cb8270f2c7
    Resource folder writeable: Yes
    SCRIPT_NAME: /mind/core/settings/diagnostics/index.php
    REQUEST_URI: /mind/core/settings/diagnostics/
    DOCUMENT_ROOT: /Users/garrettc/sandbox/polytechnic.co.uk/htdocs
    HTTP_HOST: polytechnic.dev