I've added a newsletter sign-up with 10% discount on my online store and I have enabled DOUBLE OPT IN. However, when I put my email address and receive email confirmation to confirm my subscription, it takes me to my online store and then the newsletter sign-up, pops up again and it requires to re-enter the email address which is quite annoying.
Also when I uncheck DOUBLE OPT IN, I don't receive any email confirmation. Apparently, it only sends email confirmation if DOUBLE OPT IN is enabled.
Feel free to visit my website. However, I have disabled the newsletter pop-up until it's fixed.