I too have a 2023 1500 Denali Ultimate that is now having the exact same problem. Mine has ~8k miles now and it has worked perfectly until yesterday. I recently had to pull a defective battery but I dont know why that would cause a problem. GMC does use dynamic sensors (as opposed to static sensors used by most Japanese car makers) and so it does take them time to "calibrate" themselves but it doesn't make sense that Supercruise works fine but will not change lanes. Any help or further updates would be much appreciated.