iPhone 5s orientation stuck to what it was before locking screen

Dear all,

I'm having some issues with the screen orientation of my iPhone 5s running iOS 8.1.3. Just wanted to check on whether that is an issue with my device only or it is bug.

Try this:

1. With the iPhone in portrait mode open an app that supports screen orientation (i.e. the calculator)

2. Turn your iphone to landscape position. The calculator will re-orient accordingly

3. With the iPhone in this position lock the screen

4. Turn the device in portrait position and unlock the screen. The calculator will still be in landscape mode and will not turn back into portrait unless you turn the device to landscape and then back to portrait.

This is annoying. It works correctly in my 3GS running iOS 6.1.6

Comments?

Thanks