Forum Human Verification for Registration not working
 

I have "Register" checked in Human Verification Options, and I'm using the Question and Answer Verification method as it's a small community with a shared knowledgebase so it's easy to come up with questions only we know the answer to.

I've been getting a flood of bogus registrations, and on testing the Q&A challenge is not appearing - this seems to be something new. Thoughts on what option I'm missing to make this work?

Human Verfied Actions, Register is checked.

Human Verification Options: Question & Answer Verification, I have a question and an answer configured.

Thoughts?

Thanks!