Colorbox images not sequencing

I am having difficulty getting Colorbox to sequence through a group of images on a few of my websites.  I have tried variations of Colorbox implementations using Brilliant Gallery, using the Insert module, and my own HTML.  Works fine on most of my sites, I can't find what the difference is.  They worked at one time, I am not sure what changed.  I have gone through the Colorbox screencasts to make sure I'm not missing anything:

• Colorbox for Drupal 7, part 1: Installation and image field integration on Vimeo
• Colorbox for Drupal 7, part 2: Inline images with the Insert module on Vimeo

And today for a test along side watching the screencasts, I have created the following code using Colorbox with the Insert module on the test page http://www.jbdconstruction.us/test 

<a href="http://www.jbdconstruction.us/sites/default/files/IMG_1058.JPG" title="Test" class="colorbox colorbox-insert-image" data-colorbox-gallery="gallery-all">
<img src="/sites/default/files/styles/thumbnail/public/IMG_1058.JPG?itok=y1OuR07v" width="100" height="75" alt="Test" title="Test" class="image-thumbnail" />
</a>
<a href="http://www.jbdconstruction.us/sites/default/files/IMG_1062.JPG" title="Test 2" class="colorbox colorbox-insert-image" data-colorbox-gallery="gallery-all">
<img src="/sites/default/files/styles/thumbnail/public/IMG_1062.JPG?itok=9BfOtC0t" width="100" height="75" alt="Test 2" title="Test 2" class="image-thumbnail" />
</a>
<a href="http://www.jbdconstruction.us/sites/default/files/IMG_1060.JPG" title="Test 3" class="colorbox colorbox-insert-image" data-colorbox-gallery="gallery-all">
<img src="/sites/default/files/styles/thumbnail/public/IMG_1060.JPG?itok=U72UuFR1" width="100" height="75" alt="Test 3" title="Test 3" class="image-thumbnail" />
</a>

If you check the test page you will see that it works fine except there is no "Next" or "Previous" buttons?

Drupal 7.56, Colorbox module 7.x-2.13, Insert module 7.x-1.4, Colorbox plugin 1.6.4.  No clues in dblog.

Please help, many thanks in advance for any suggestions!

Mike