@lena01 You didn’t read my post. I have disabled the captcha keys, but this is only a temporary solution (I don’t want to have spam).
@codekraft (Erik) I had already tried disabling the two add-on plugins for Contact Form 7, but that doesn’t make a difference. The issue must be with “The 7” WordPress theme, as the error message displayed is the one in the contact forms configuration of this theme.
I don’t want to try moving back to a standard theme, as this can sometimes cause issues.
As this was working previously with Contact Form 7, and The 7 is one of the most popular WordPress themes in the market, perhaps it’s the Contact Form 7 responsibility to ensure that new releases perform well with the top 5/10 WordPress themes?
As the problem does seem related to the theme, but is probably an issue between the theme and Contact Form’s 7 code for Recaptcha V3, not sure what I can do now. This issue seems to be quite common (seen many other support requests).