After the update to iOS 11.1.2 pe iPad, I noticed that Dock disappears from Home Screen, can be made visible with a swipe (Drag) from up to down, started from the bottom of the screen. I mean, the same thing I was doing normally to make the Dock Bar visible in an open application on the iPad.
Initially I thought it was a feature of the new iOS and that this "auto hide" can be disabled in Settings. Surprise! In "General" → "Multitasking & Dock" there is no option to prevent automatic hiding and Dock in Home Screen.
From what I found out, this is not a feature of iOS 11, but a bug that appeared after the latest iOS update. "Disable auto hide iPad's Dock in Home Screen".
Solving the automatic disappearance of the Dock from the Home Screen can be solved very easily with a total closing of the iPad and reopening. Hold down the button "power / Sleep"Then"slide to power off". After rebooting, Dock will appear in the Home Screen and will be withdrawn only when you are in an application.
In our case, the problem arose on a iPad Mini 4 iOS 11.1.2.Disable Auto Hide iPad's Dock in Home Screen - iOS 11