Unable to pass captcha after it failed once. It does not take the second input

Hi

I've tried using captcha + captcha riddler on my site.
While testing I tried the following experiment that always failed:

1. Under the anonymous user try posting a comment to a forum thread. Fail captcha (simulate user mistake). "Invalid captcha token." is correctly shown
2. From the same page try solving the captcha challenge correctly. Still comment fails to be posted and "Invalid captcha token." is shown again

I think that that captcha doesn't even try evaluating the second time input for the following reason: If in admin I set "Omit CAPTCHA for a form once the user has successfully answered a CAPTCHA for that form." the second time captcha textfield is not shown at all. I.e. even though the captcha challenge was failed the captcha process was kind'of over and module didn't expect the second trial at all.

I reproduced this problem both on 5.x-3.x-dev and 5.x-3.0-rc3

I hope this information helps to resolve the issue.

Best regards,
Artem.