Runway: page_links not outputting for collection

I have a paginated collection. Everything is working except for <perch:content id="page_links" encode="false" /> which doesn't seem to be outputting. <perch:showall/> shows page_links as blank:

<perch:showall/>:

paging  true
total   26
number_of_pages 2
total_pages 2
per_page    18
current_page    1
lower_bound 1
upper_bound 18
prev_url    
next_url    /products?page=2
prev_page_number    
next_page_number    2
first_page_url  /products
last_page_url   /products
first_page  true
not_last_page   true
page_links  
perch_item_first    true

Page:

                <?php perch_collection('Ring & Pinion',[
                    'sort'=>'title',
                    'sort-order' => 'ASC',
                    'paginate'=>true,
                    'count'=>18,
                    'page-links'=>true,
                    'page-link-style'=>'all'
                ]); ?>

Template:

<perch:before>
<perch:if exists="paging"><div class="paging">
    <perch:showall/>
    <perch:content id="page_links" encode="false" />
  Page <perch:content id="current_page" type="hidden" /> of <perch:content id="number_of_pages" type="hidden" />
  <perch:if exists="not_first_page"><a href="<perch:content id="prev_url" type="hidden" encode="false" />">Back</a></perch:if>
  <perch:if exists="not_last_page"><a href="<perch:content id="next_url" type="hidden" encode="false" />">Next</a></perch:if>
</div></perch:if>
</perch:before><a href="/products/ring-and-pinion/<perch:content order="2" id="slug" type="slug" for="title" editable="true" indelible="false" label="Slug" help="Appears in product URL" />">
    <span class="img" style="background-image:url('<perch:repeater order="4" id="images" label="Images"><perch:if exists="perch_item_first"><perch:content type="image" id="image" label="Image" width="800" quality="80" bucket="ring_and_pinion" /></perch:if></perch:repeater>');"></span>
    <span class="info">
        <strong class="font-dinpro-medium"><perch:content order="1" id="title" type="text" label="Title" required="true" title="true" /></strong>
        <span><strong>Part#</strong> <perch:content order="3" id="part_number" type="text" label="Part Number" required="true" /></span>
        <perch:if exists="equivalent_product"><span><strong>Lightning#</strong> <perch:related order="9" id="equivalent_product" collection="Ring & Pinion" label="Lightning/Non-Lightning Equivalent" size="m" ><perch:content order="3" id="part_number" type="text" label="Part Number" required="true" /></perch:related></span></perch:if>
    </span>
</a><perch:after>
<perch:if exists="paging"><div class="paging">
    <perch:content id="page_links" encode="false" />
  Page <perch:content id="current_page" type="hidden" /> of <perch:content id="number_of_pages" type="hidden" />
  <perch:if exists="not_first_page"><a href="<perch:content id="prev_url" type="hidden" encode="false" />">Back</a></perch:if>
  <perch:if exists="not_last_page"><a href="<perch:content id="next_url" type="hidden" encode="false" />">Next</a></perch:if>
</div></perch:if>
</perch:after><perch:content suppress="true" order="5" id="ratio" type="text" label="Ratio" divider-before="Specifications" /><perch:content suppress="true" order="6" id="tooth_count" type="text" label="Tooth Count" /><perch:related suppress="true" order="7" id="family" collection="Ring & Pinion - Family" label="Family" size="m" divider-before="Sorting" ></perch:related><perch:content suppress="true" order="8" id="lightning" type="checkbox" label="Is this a Lightning version?" value="yes" />

Diagnostics:

Perch Runway: 3.0.8, PHP: 5.6.14-1+deb.sury.org~trusty+1, MySQL: mysqlnd 5.0.11-dev - 20120503 - $Id: 3c688b6bbc30d36af3ac34fdd4b7b5b787fe5555 $, with PDO
Server OS: Linux, apache2handler
Installed apps: content (3.0.8), assets (3.0.8), categories (3.0.8), perch_forms (1.9.1)
App runtimes: <?php $apps_list = [ 'perch_forms', ];
PERCH_LOGINPATH: /usg-admin
PERCH_PATH: /var/www/public/usgear.dev/usg-admin
PERCH_CORE: /var/www/public/usgear.dev/usg-admin/core
PERCH_RESFILEPATH: /var/www/public/usgear.dev/usg-admin/resources
Image manipulation: GD Imagick
PHP limits: Max upload 2M, Max POST 8M, Memory: 128M, Total max file upload: 2M
F1: 0c66c2e1f82f9e0b7617b2cb8270f2c7
Resource folder writeable: Yes
HTTP_HOST: usgear.dev
DOCUMENT_ROOT: /var/www/public/usgear.dev
REQUEST_URI: /usg-admin/core/settings/diagnostics/
SCRIPT_NAME: /usg-admin/core/settings/diagnostics/index.php