I tracked down the issue and we have a fix that will be rolling out shortly.
The good news is there are NO privacy impact here. It was an issue with the settings page.
The bug was introduced by changes we made last week to how the default for that setting is determined. It used to always be ON. But we now default to OFF for newer browsers that support the meta referrer tag. The meta referrer tag solves the same privacy issues in a much more elegant way, you can read more about it here: https://blog.mozilla.org/security/2015/0...
The reason we wanted to make the change is because not sending every click through the redirect will make using DDG way faster without sacrificing on privacy.
Both FF38 and Safari on newer versions of iOS support the meta referrer tag, which is why you were seeing the setting off by default.
After the fix rolls out you should be able to opt back into using redirects if you want. However, we don't think it's necessary. We're also going to update the description on the settings page to reflect these recent changes.
Thanks again for your helping finding this!