Hey Jeremiah,
Welcome to our Support Forum and thanks for writing in.
Regarding the issue, it’s highly likely a setup problem on Mailchimp’s end because once you integrate the code correctly the first time and it works, that means the integration is correct. Our theme will just output the code you insert to it. It does not affect the function of any custom code so if on the second time your code doesn’t work anymore while you did the same exact integration, that means there’s a problem with the functioning of the code.
First, please try clearing all caches, log out of WordPress and load your site and see if the popup will work again. Also, try in the browser’s incognito mode and other browsers.
If the popup doesn’t work, please contact Mailchimp support if there’s an expiration setting. An expired popup could mean that you won’t see it anymore once you’ve seen it. That depends on Mailchimp or any email service provider. If there is no setting for that, please consult with a third-party developer.
Please note that because Mailchimp is a third-party service, we cannot provide support for it and this is not an issue with our theme because as I’ve mentioned, our theme only outputs the code you insert to it so it does not affect the function of any custom code.
Just in case your open to use another plugin, I’d recommend you try ConvertPlus. It’s an alternative to our Email Forms extension and it is bundled in our theme so you could use it for free. For more details about ConvertPlus, please see https://theme.co/docs/convertplus
Hope that helps.