The chords you've set up in the Signature track affect the display of key changes in the score editor but do not change the sound of the notes.
You might have better luck using the Transpose field in the Region inspector (yellow arrow to the left), or explore using the Transpose track (yellow arrow above). Neither of these options will change a major to a minor chord. You can change notes in the Piano to alter the sound. Changing one note down a half step might give you the sound of the minor chord that you want.
Thank you for your answer. I was afraid that that was the cause. It’s a pity because it could have been a great feature. I dont use transpone but pitch to select the right notes from a chord. I’d recommend if you already know the chords u want to use.