When you use Popcorn Time, you'll always see this small tab that says “TURN ON VPN”. This happens despite the fact that you're already connected to a VPN. There's no exact way to stop this issue, but it's noticed that it occurs mostly on the new version of the Popcorn Time app. You can try reverting back to the older version if it bothers you a lot. However, if you use a renowned VPN service, like the ones mentioned on my list, you could finally get rid of the pop-up warning.