Boxilla is overriding MailChimp redirect

With mailchimp forms on my site I’ve set up a redirect so that once someone signs up using the form, they’re then taken to a different page using the redirect option. However when that same form is placed in a Boxilla pop-up box, after the person signs up, the box adds a thank you message, but the redirect to the new page doesn’t happen. It’s like Boxilla is overriding the MailChimp redirect. Is there a way to get Boxilla to allow the redirect once someone has signed up?