It means that when the forum asked recaptcha whether you actually answered it correctly, recaptcha said no. IP change is a possibility.
Yuph, I'm not using TOR for browsing. But I think the main problem why TOR keep saying "An error has occurred" and "incorrect recaptcha" is because of IP issue. Tor uses different IP's as it keeps you anonymous to the web. That's why everytime it loads/changed the recaptcha, the IP changed as well.
By the way OP, do you just encountered this issue recently? Are you not having trouble in recaptcha in the past? Because there is a possibility that this is a browser issue.
Clear cookies,install brave browser,reset modem,dont login in Google email.This help me.
Brave browser is a good browser to stay anonymous, but besides from Tor browser, you can try firefox focus as well.
I have been having problems with the "try again" or "connection error" stuff within the captcha box before. Like I said before, this message is within the forum, not within the captcha box, and it happens after you get a green checkmark of a successfully completed captcha.
The only logical explanation is that the IP changes right after you complete the captcha, so once you press "login", you are already using a different IP, so the forum gives you that error. What I don't understand is that this happens even after I change IP sometimes, and as far as I know Tor only changes IP automatically every 10 minutes..