@Anonymous User
Welcome to the forum. Not heard any issues. Are you sure this is happening when you are in the NOW TV app? Which devices do you have? The two devices streaming at the same time limit applies to the NOW TV app but the Sky Store app only let's you watch rented movies on one device at a time.
If it is happening in the NOW TV apps try signing out of the app and back in again, and make sure when you finish watching something you back out of the stream using the back button rather than quitting unexpectedly using the home/quit button for example.
