Firefox Issue - Protected Content Page Displays Even When User Is Logged In

Hi,

First and foremost - my membership system works seamlessly in Chrome and Safari. It's firefox that it's not working in. Secondly, I'm using WP Engine as my host. They're currently investigating, but I found another ticket with similar issues on WP Engine and Firefox for Mac.

My site is set up so that only members can view the gallery. Works fine in firefox and chrome, they get hit with a protected content notice if they are not logged in.

However in firefox, even when they're logged in, they get hit with a protected content notice. Any thoughts on how I can fix this?

I'm only using one negative rule for anonymous "visitors" which blocks access to that page. And it works fine in chrome and safari so that means it's configured properly...

Thanks