Presumably, these are the costs of mini-LED backlighting
In April , Apple introduced the iPad Pro tablet on the Apple M1 SoC with a 12.9-inch Liquid Retina XDR display. This display is interesting in that it uses a mini-LED backlight consisting of 10,000 miniature LEDs. Peak screen luminance is 1600 cd / m 2 , the contrast – 1,000,000: 1.
Some Apple iPad Pro Buyers Report Overglowing Liquid Retina XDR Display
Although the display is praised in many reviews, some users have encountered an issue that can be described as excessive luminescence. As seen in the images posted by one of the victims, light elements against a dark background acquire glowing blue halos, giving the impression that light is “leaking out” from under the dark areas. Apple’s support site says it’s okay, but the effect should be minimal. It is hardly possible to characterize its manifestation in the above photographs.
The source suggests the problem is hardware, so it’s unclear if Apple can fix it with a software update.