I have a 2020 XT5, had to take it to the specialist at U Break we Fix it and the Cadillac Dealer. They corrected most of my files. My 2011 Buick played all my Files on my Flash drive regardless of the format that was used, it had the Harmon Karmen system. I had heard that Cadillac changed there download system in 2020. Hopes this helps a little.
