MailChimp popup not working

I want to generate a popup on my website to capture emails.
I followed mailchimp instructions to connect my site by adding the generated code before the /head tag and it gives me the error “Uh oh, we couldn’t connect your site. Check your code and try again.”. I tried disconnecting and deleting everything and trying again and it still does not work.
Weird part is that it used to work 2 months ago and I recently noticed it stopped working