Key sticking on Facebook

Quit the FaceBook app completely and restart the iPad. Go to the home screen first by tapping the home button. Double tap the home button and the recents tray will appear with all of your recent/open apps displayed at the bottom. Tap and hold down on any app icon until it begins to wiggle. Tap the minus ➖ sign in the upper left corner of the app that you want to close. Tap the home button or anywhere above the task bar. Restart the iPad.

Restart the iPad by holding down on the sleep button until the red slider appears and then slide to shut off. To power up hold the sleep button until the Apple logo appears and let go of the button.

If that doesn't help, try rebooting the iPad. Reboot the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons.