Indeed this can happen as the amount of added captcha types grow and they might look simular (same size/colors used). In that case it becomes difficult for CB to choose the correct one. The one with the best match however is used first before others are used to solve things. What type in particular?
OK, not much that can be done here other than you check the option to treat all unchecked captcha types as not being present and you uncheck those where you think they are not relevant for you. But usually CB has a good detection to choose the right type and sort them in priority.
Comments
Thank you for explanations.