Hi again,
To solve the problem, please try to regenerate new keys for the site https://www.google.com/recaptcha/admin#list, and check if the problem still occurs.
If it does, then:
1) Please try activating a standard WP theme for a while (2014, 2015) and check if the problem remains. Please let us know about the results.
2) Please try deactivating all of your plugins except Google Captcha (reCAPTCHA) and also check if the problem is still present. If it is not, please activate the plugins one-by-one, meanwhile checking, after which plugin activation the problem appears again.
3) Please specify a link to your website and provide your System status as well. Follow the next instruction – https://docs.google.com/document/d/1Wi2X8RdRGXk9kMszQy1xItJrpN0ncXgioH935MaBKtc/edit
Sincerely,
BestWebSoft Support Team