Does any one have a solution for electronic key not detected i

2008 CTS4 electronic key not detected replaced
key fob batteries no luck .  Also tried
reprogramming the key fobs with the slot under the
arm rest no luck . When u get to the last step for
the car to read the key fob it just say ready to learn
key # 1 or # 2 but the key is in the slot under the
arm rest the car still isn’t detecting it .  The cars
battery is fine it’s holding full power every thing
works on the car it just will not detect the key fob
so the ignition won’t even turn at all . Anyone else
had this issue before all I keep seeing is everyone
saying change the batteries but no REAL solution
as to why the car still doesn’t detect the fob after
new batteries have been put in the key fob .  I’ve
already located the remote control door lock
receiver in the back of the car on the rear deck by
the subwoofer .  But before changing I wanted to
know if anybody had this issue and solved it with
anything other then changing key fob batteries ? PS
never buy one of these cars from 2006-2019 they
are ( trash )