yes they can walk forward, backward and sideways,
both
The pedal at your right foot. Press forward to go forward and back on a heel tread to go backwards.
"Forward deployed"
usually forward but if you shift to "R" then they go backwards
sounds like a transmission problem to me, clutch or g'box? dunno why it works when its hot, maybe the clutch slips more when its cold???
The winners in a "tug of war" go backwards
Release the parking brake and either use the hand lever or the foot pedal. Push the hand lever forward to go forward and back to go back. If a foot lever then forward pedal to go forward then rear pedal to go backwards. You won't be able to have the blades engaged to go backwards unless you use a bypass if it's there. The throttle should be near the steering wheel.
It does not go sideways!
ENGINE
The main drive belt/chain may be broken or jammed.
stand straight forward and move one foot to the other, do this multiple times moving left or right as you go along.
Check the fluid level. If the level is up, the transmission has probably failed.