How are bots bypassing my ReCaptcha?

#1
I own several websites and my ReCaptchas effectively block spam emails on all contact us pages except for one:

https://www.instant-rsvp.com/contact.html

Several times per week I get an email through that contact form that looks a little something like this:

spam.png

This seems to be a textbook spam bot because of the fragmentary and almost random blurbs of text, with links injected that they presumably want people to click on.

So I experimented with that contact page to see if maybe my ReCaptcha wasn't working. But I am unable to submit a message to myself without correctly validating. This problem doesn't occur with any of my other website, some of which I'm pretty sure get more hits in general than this site.

Any ideas how the spam bots are defeating my ReCaptcha? Is it possible that some human is going to the time and trouble of manually sending me this garbage every day?

Thanks in advance for any ideas.