I assume you are presssing on the brake pedal when you are pushing the button and trying to move the shifter? A cable goes from the brake pedal arm to a release mechanism on the shifter. Inability to move shifter is commonly caused by working under the dash and moving or disrupting the cable or the mechanism under the center console getting out of alignment. Try wiggling the cable (looks like a bike bradk cable) under the dash before pulling the console.