Have you tried a forced software update by going into the box secret menu, by pressing the Home button on the remote 5 times, then quickly press the FF button 3 times, then quickly press the RW button 2 times.
Once in the secret menu update the software even if you are on the same version number.
If that doesn't work, go into the NowTV App on the box, then go to the My Account section inside the NowTV App, then sign out of the box.
Once logged out, switch the power off to the box for about 30 secs, then re start the box and then go back into the NowTV App and re sign back in again to see if any of your movies work on the cinema pass.
Also, once signed back in on the box under My Account double check that it says " Start Watching" Active Cinema Pass and not something like " Buy Pass or Start Free Trial".