Chosen Solution
Got the LCD replaced today and everything works fine till the screen either times out or gets locked. after locking when I try to unlock the iPad the screen stays black but if I plug it into the tv with a hdmi adapter the screen shows up on tv and digitiser does work. If I restart the iPad it works again till it locks. running 12.1.1
What happens when you try holding the power button when it gets stuck on the black lit up screen? Does it show the slide to power off prompt? Does the home button work at all on that digitizer? This points to a bad replacement digitizer where the smart cover sensor is faulty or missing on it. Might need to cover the bottom digitizer border and home button cable with kapton tape so that the home button does not short with the digitizer or iPad housing.
