For a while now I have been noticing this, and not just on the SE network, but all the sites that use the new re-CAPTCHA system, and I have tested this on many different OSs and also many different browsers, but the problem still remains, most of the time if I click on the button which should give me a CAPTCHA test, it just does its spinning thing, then shows a big green tick and allows me to continue without actually testing me (this happens probably 98% of the time). So where should I report this issue?
That is part of reCaptcha's system, I believe. And because of that, the people to report that issue to is reCaptcha, especially if it's global across all the reCaptcha things you see.
Note that I don't think they always force you to do a captcha check, at least not on all sites. I get reCaptchas on some sites that require actual captcha checks, others I just have to click the box. (Although I never have to captcha check here on StackExchange sites.)