Just solved the problem. Wrote down if someone else get this problem.
Looks like if the Liftgate glass doesn't close properly (or the sensor feels not). The side effect is the power
liftgate handle won't work. Mine won't open from driver's button neither. If you force it open manually, it
can close by push the power button.
So I got in the car, pushed to open the Liftgate glass, and close it. It pumped back pretty hard when close
it, then the message "Liftgate glass open" disappear, then the power Liftgate handle works again.
I never opened the glass and didn't know it would open neither. But I left my inside back light on during
last night without knowing it, so someone may tried to open the Liftgate or released the glass open handle
(it's on the right side of the Liftgate handle.) Just my guess though.
Anyway, the answer is "open the Liftgate glass, and close it." Done.
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