Honda Harmony 2013 Riding mower transmission issue?

I was backing up my 1998 Honda Harmony riding mover (2013HSA) and the left rear wheel hit a tree (not going fast). Not 100% sure backing into the tree was the cause however now the mover will not start in neutral (it is an automatic/hydrostatic). Now when I try to start it in neutral the wheels start to turn. I have to move the transmission shift lever out of neutral, up a notch or two, and push the neutral button in by hand, the button that is normally pushed in when the transmission is in neutral, to allow the mower to start.

Looking at the components, nothing looks broken. The mower will start and ride (with adjustments mentioned above). I just want to fix this problem as basically running my Honda without a neutral can be dangerous.

Any ideas what need to be done?

Thanks for any help.

Honda Harmony 2013 Riding mower transmission issue?