iPad Air2 Color Banding, Posterization

Yesterday my iPad display began to have color banding, posterization issues. The images and videos in safari would appear dark and grainy. On some websites I can see a thumbnail change from “normal” to “dark/grainy” once the webpage loads. This issue extends to the camera. Photos taken appear dark and grainy in well illuminated rooms. When I select the photos for deletion, the thumbnail changes from “dark/grainy” to “normal” which surprised me. I have tried rebooting the iPad (power+home). I have tried diagnostic mode (volume up+home). I have tried dropping the iPad on carpet at 2 foot height. I have toggled a number of display settings, auto-brightness, reduce white spot, increase contrast, reduce transparency, reduce motion, etc., which has optimized my iPad processing speed but has not fixed the color banding, posterization underlying issue. I installed a benchmark app from the app store, compared my iPad test results with a youtuber test results, my iPad test results were off by hundreds; I read that is a processor issue, hence why I tried the iPad optimization approach. When I toggle auto-brightness the screen dims to a near display turn-off state, so I manually increase the brightness. Is there anything I can do to resolve this color banding, posterization issue?