Hello @dvankooten,
Thank you for your response. Yes, I managed to resolve it:
1. First I rollbacked the plugin to version 4.5.5. But that didn’t cut it.
2. So I updated to the latest once again and tried to turn off the global recaptcha, without prevail. Same error in the debugg logg. Turned on the recaptcha again.
3. Checked if any other plugins had recaptcha enabled. After a long search I remembered that there’s a recaptcha options in the form settings for MC4WP. There I had a recaptcha v3 enabled. I doublechecked the sitekey and secretkey, which were correct. But I turned it off for the form and after that the signups worked again flawlessly.
Guess I cried wolf on that one. Still don’t know why the recaptcha classified my own signup efforts as spam, and some signups work.
