Hustle will not work

Please note this is a live site and I don't know how to do plugin conflict testing advised by the live support team.
This is my issue:
I’m trying to set it to popup after 30 seconds and collect emails from my mail chimp list, but it is not popping up most of the time (I am clearing cache to test as I have cookies set to show only once per visitor). Also, when it did pop up, it doesn’t seem to be adding some of the emails to my mail chimp list.
I have tried every setting possible, Hustle will not work.