CAPTCHA Bot Threshold is Always Zero

I’ve recently implemented reCAPTCHA on my login pages for a client and had them email me today, irate that the couldn’t login to the site without clicking a link in a verification email. For whatever reason they were not receiving the email, but that’s neither here nor there. Their perfectly normal login procedure was being seen as suspicious and they were having to verify. I tested with an account with similar privileges and found the same thing.

Investigating further, I see that, in Wordfence, it appears that all the login attempts are being given a human/bot threshold score of 0.0 (definitely a bot), so regardless of how “bot-like” they appear, they are always asked to verify. Checking in Google reCAPTCHA, the human/bot threshold score of all those login attempts is 9.0 and there haven’t even been any attempts that qualify as “high risk”.

What’s the deal here? Has anyone else had this problem?