Nothing gets queued for purging

Problem/Motivation

I can't seem to get anything to be added to the purge queue. drush pqv keeps telling me there are 0 items in the queue, even right after editing a node, modifying a view, or moving a block.

Steps to reproduce

* Install Purge and Varnish Purger
* Enable Purge UI and Varnish Purger
* Add Varnish Purger Purger on admin/config/development/performance/purge. (Set the request to my varnish server using the BAN method. Configure the headers with "Cache-Tags" and " [invalidation:expression]", I've tried both the tags and path types.)
* Add a new basic page and confirm it is cached by Varnish.
* Edit the basic page.
* Run `drush pqv`.

I should see at least 1 item in the queue. At least I think. I'm guessing I'm missing a step.

I have been watching the varnishlog for any BAN requests. None go through unless I run a manual invalidation via drush. So it isn't that the queue is getting emptied immediately.

Proposed resolution

Point out what step I missed, or figure out there's a bug...

Thanks in advance, I spent most of yesterday experimenting and searching to try and figure this out.... So help would be very appreciated.