Problem with gear drop and misfire codes

I have a 2011 enclave with 132k miles that I fixed all the motor issues on, put in new timing chains, plugs, coil packs, water pump, etc. I even switched out all the wave plates in the transmission. My problem is that when I drive it around it runs and shifts great as long as you ease into it but if you get into it, it kicks down a gear and revs out and stays there until you back out of the pedal all the way and let it catch the gear again, in the process of when it does this it throws random misfire codes, it also can not maintain cruise control either. If anyone has an idea that might point me in the right direction to fix it I would greatly appreciate it. Thank you