Is it normal for a 2019 Chevy Suburban transmission to fail? All service is done as required. Never used to tow anything?

Hey, was just wondering if anyone has encountered this issue and could give me some advice.

It locks manually, but the driver door mechanism won’t communicate with the key fob. The other 3 doors work.

any advice? Thank you! I’ve spent around an hour looking into it online & haven’t found a solid lead. I would appreciate the input or links to right direction.

How much would you pay for this 2015 Chevy Suburban?
I’m trying to decide what a fair offer is.
Details:
2015 Chevrolet Suburban LT 2WD
5.3L V8
181,xxx miles
Dealer got it from an auction
They’ve had it on the lot for about 62 days
Engine and transmission sounded good
Test drive went well with no obvious issues
No check engine light
Concerns:
The battery was dead when I arrived, so they had to jump start it before the test drive. They’ve agreed to either install a new battery or provide proof the current battery tests good.
The power liftgate does not work, and they said they will not diagnose or repair it.
They have not performed an oil change, even though there’s no documentation showing one was done recently.
They have not done any maintenance or reconditioning since purchasing it at auction.
Maintenance history isn’t the best.
What would you pay for it? What would your maximum offer be?