OK, I have also installed a 12 inch from an 8.4 and have the same issue. So how do i set my vehicle to 2019 like you did? I do not mind the zoom not being there.I had/have both of these issues. Making sure the vehicle year in the BCM was appropriately changed back to the year of manufacture (2019 for me) solved my backup guidelines issue. I just realized yesterday after reading another forum that I no longer have the “hitch camera” and haven’t figured that one out yet. Hope this helps.