It looks like this is an apple designed "feature". It's not a hardware problem it's a software design. When you replace the original screen, it has an apple pencil chip which is serial number matched with the original iPad.
Unless the repair shop doesn't remove this chip and put it into the replacement screen, everything will work except the apple pencil (which produces jittery lines with diagonal strokes).
The only way to get a perfectly working screen is to get it repaired from apple (which now won't work because they refuse to touch any 3rd party repaired device)
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I got to know about this system when I got my iPad air 5 repaired with a screen from a donor iPad air. Apple is really really hell bent on not letting users get their apple stuff repaired for cheap.
It looks like this is an apple designed "feature". It's not a hardware problem it's a software design. When you replace the original screen, it has an apple pencil chip which is serial number matched with the original iPad.
Unless the repair shop doesn't remove this chip and put it into the replacement screen, everything will work except the apple pencil (which produces jittery lines with diagonal strokes).
The only way to get a perfectly working screen is to get it repaired from apple (which now won't work because they refuse to touch any 3rd party repaired device)