Switch to classic theme, Clear storage/cache of Mobile Manager, check Preferences> Home Screen> Lock Home Screen is disabled Can you add other 2 shortcuts? Happens to me sometimes but not when i use classic theme.
@LaurelLParas I suggest you clear cache files system-wide and then reboot your device. Turn off developer options if you have them enabled and see if that makes a difference, should the first step not work. Settings -> Advanced -> Mobile manager -> Cleanup