I’m using Redmi Note 4G. In the task manager, I noticed there’s a small lock icon in the upper right corner on the Messaging app. And, whenever I tap X to remove all apps, the Messaging app isn’t removed. Can you please tell me how to remove the lock on the Messaging app?
In MIUI, you can lock an app in the task manager and keep it running in the background. The locked app will show a small pad lock icon in the upper right corner.
You can lock an app by swiping down on its icon, and then do the same gesture to unlock it. So for your case, simply swipe down on the Messaging app one more time to unlock the app.
In addition, you can also remove an app from the cache, regardless it’s locked or unlocked, by swiping up on ts icon.
For more information, see MIUI 6: How to use Task Manager to switch between open apps?