This is definitely a bug. It worked correctly on my previous phone under Android 5.1 but my XZ1c is having issues on both 8 and 9. With Ask for Pin Before Unpinning ON: 1. Pin screen 2. Press power button to disable display 3. Then press power again to turn the screen back on Expected behaviour: 1. Pinned app is shown 2. When app unpinned phone prompts for pin to continue using device Actual Behaviour: 1. Phone asks for pin immediately on wake. 2. App can now be used in pinned mode 3. Unpinning app gives full access to device without reprompting for pin. As it currently is screen pinning is mostly useless for its main use case.
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