After converting a site to be served over TLS, we noticed the drop off rates increasing on some pages. This was because: user was being redirected to a payment page on another domain that was also served over TLS. As, now both sites were served over TLS, Google Analytics was picking up the referrer (HTTPS -> HTTP would pass no referrer, HTTPS -> HTTPS does) and was counting the payment page/domain as a new source. Thus, counting the redirect as an exit. Fix was simple, I excluded the payment domain in the referral list.