Non-Contact Initiated Decision Path terminates campaign?

Hello all,
Question. Is there a way to backtrack a user who’s gone down a non-action initiated decision path (red connectors in campaigns?). For example, if I want a user too fill out a form, and after they do so they get some emails directing them to do other stuff. But if they don’t fill out the form within 21 days, I send them down the Non-action Initiated Decision Path that sends them a “need help?” email.
So let’s say the user doesn’t fill out the form within 21 days, gets the need help email, then goes and fills out the form. Shouldn’t they then continue down the Contact-Initiated Decision Path (green connectors in campaigns) and receive the next emails telling them what to do next?
I’m finding that not to be the case. It’s terminating once they get the “need help?” email even if they go and submit the form which should allow them to carry on.
Any advice on how to do this correctly so the user continues on in the campaign once they submit the form?