Membership 2 Pro - unable to restrict media content access

Hi There, I asked this question already, but support staff seems to have disappeared for me... so I'm asking again!

I've set up 2 membership groups... Default and Restricted. I gave the Restricted Group access a particular media upload (a pdf), but i'm still able to see it when logged in as my test Default member. You can even see it in the Media Library. I must be missing something... Help would be appreciated!

I tried disabling all other plugins, and switching to the default theme, but same thing. Site is being hosted by WPEngine.

I could really use some help figuring out why this plugin isn't working for us!