CB AntiSpam - reCaptcha v2 (google) not visible on secure page

CB AntiSpam 3.1.0+build.2018.02.15.15.47.42.e96dba412

I have the google reCaptcha v2 enabled for my Community Builder login.
I have a menu item thats loads an article which has a custom module position that loads the Community Builder Login module.
If I set the menu Meta Data Secure option to On the reCaptcha does not display. With secure set to No it displays fine.

My site is currently in development and I'm using a self signed SSL cert. Don't know if this is relevant.

Appreciate a steer on where to look to troubleshoot

Update:

Don't know why but this issue has resolved itself.

Played around with the menu item assignment changing from Public to Guest.
I also have the CB_Login module loading directly into another part of the site and this module didn't have the CB Plugin integration enabled, so experimented toggling this.

Whether either of these changes had anything to do with the issue I'm unsure as I can no longer reproduce the problem with whichever combination of the above to settings I enable.

I'm guessing it was due to caching or the profile endpoint wasn't reachable for a public user making the ajax call fail to load the captcha.