To keep form maintenance under control, we thought it was wise to create a central form for (e.g.) webinar registrations that lives in the Design Studio. In the webinar program we've created a local Landing Page with the central form on it. We then listen to this central form being filled out (Trigger: Fills out Form), with Form name = 'central form' and Constraint: Web page = 'local Marketo LP'. People who will out the form will be marked as Registered as a result.
I now see that half of the members is Member of the program, but not Registered. So it seems the Trigger as described above doesn't work in all cases. I vaguely recall having met this problem before, and adding a second trigger Fills out Form, with Constraint: Referrer = 'local Marketo LP' may solve the problem (I'm monitoring it as we speak).
However, I just don't understand whether my setup is simply incorrect or what else may be causing this.
Any insights much appreciated!