It generally does connect whatever it connected to last assuming both are present . It will switch when you don't want if one of you leaves the car for a bit with your phone to store and leave your spouse behind....
You could try flushing all the car based bluetooth and carplay connections stored on the Palisade itself and see what happens.
Other notes: You might want to make a habit of putting phone on charger tray near the carlinkit. I could see that sometimes having the phone jammed in left or even right pants pocket perhaps additionally behind your wallet cutting down bluetooth/wifi strength enough to make the spouse phone the stronger signal to lock onto.
You could try flushing all the car based bluetooth and carplay connections stored on the Palisade itself and see what happens.
Other notes: You might want to make a habit of putting phone on charger tray near the carlinkit. I could see that sometimes having the phone jammed in left or even right pants pocket perhaps additionally behind your wallet cutting down bluetooth/wifi strength enough to make the spouse phone the stronger signal to lock onto.