We bought a 2020 Blazer and experienced (after just three weeks) the same problem. We had the same exclamation mark and red circle. We brought it back to the dealer and they replaced the camera. It started to work again but after 10 tests, it stopped working again. They had to order a new video processing unit but that part was on "back order." If the part is on back order, does that mean they have had numerous problems with this part? They did receive the new part and installed it. They had our car for 10 days. So far, just over three weeks, and it has been working without a problem. I did see in the news that Ford and Honda were recalling cars because of camera problems. I wonder if the camera units are manufactured from the same company. Good luck, and let us know how it goes with your Blazer.