A3 AWD Pro 3500 - error on robot being lifted

It's brand new out of the box.  The robot keeps erroring about the robot being lifted and tells me to put it on the ground, enter the PIN.  It's on the flat pavement and the PIN when entered would not go anywhere, same at the same PIN screen.  I tried the below so far:
. Hard reset
. Reset the PIN
. Flip the robot upside down, inspected the wheels, suspension.  Nothing there obvious to see.

I noticed that when pressing down the front of the robot, it's not compressed down and spring-loaded back.  It's stiff.  But if I lift up the robot with moving the wheels, they can be moved, about 0.5 inch.

I called tech support and the support agent wanted me to send back to Amazon.  I just want to know if there's anything obvious that I can troubleshoot before sending it back to Amazon

Any inputs is appreciated.