You may have to have the radio flashed at a dealership. When we get locked radios we replace them with a new radio. Radios are no longer interchangeable unless you purchase an aftermarket non-factory radio, which then an experienced installer may have to rewire. That is the purpose of the anti-theft radio's. Any time you replace the radio, it has to be downloaded into the vehicle computer. Radio's can be reflashed to unlock them, then downloaded to the car. This is my experience from working on 2016 or newer Malibu's. I suggest you call a dealer and inquire and then let us know what they told you.