I have a 2016 Chevy Tahoe ltz, one of the third row seats is stuck at a 60 degree angle, and won't fold up or down. When I press the button the motor is trying to fold it but nothing happens. And the dealership has been zero help!!

 

Not surprised. A few years ago the dealership told me "we have absolutely no idea what's wrong" when my 2005 Yukon sunroof intermittently would not close. At least I got a refund (finally) from dealership, as they readily took my money for the non-repair.

Unfortunately, the electronics keep getting more complicated every year....in your case, sounds like the motor is still turning so maybe a cable or gear teeth missing.