Ok got a weird symptom from the new A500

Did you try this?

Yes, no difference. Tried neutral for about 20 sec, then reverse, same thing, then tried a minute or two, then reverse, no difference.
But once the engine was about 1/2 way warmed up (on the gauge), then it just started working fine.
And I don't think its shifter adjustment, tried Park to Reverse, and Neutral to Reverse, either was it acts the same.