I know.. there are many subtleties here, hence why I think a 10 minute call would resolve a lot very quickly 😉
Where did the form reference come from? I'm a little confused by that?
I agree to this 100%, Jo! This problem could be solved much quicker over a call, post the details later here on the thread maybe?
Check out this message from OP where they say that the form was filled on some other CS website and people were imported to Marketo through a list import.