[SOLVED] Google reCaptcha issue

A while ago Google reCaptcha 3 started to stop working at the customer return form. It sends an error message telling "Validation is not valid. Please try again." I can't figure out why this message has started to occur. I'm using OC 3.0.3.8. Have anybody experienced a similar issue?

Usually something is incorrect or changed in the Recaptcha admin console
You can check the settings here:
https://www.google.com/recaptcha/admin

Thank you for your answer. I didn't get so many tip how to solve the issue so I did buy an extension to prevent SPAM. Works fine.