A customer discovered a problem on the first batch of these boards. A trace is touching a pad causing a motor to go only one way. If you got a board from me, before you solder the socket for the H-bridge, look at the picture below and cut along the line with a utility knife. Only the top layer is affected so when you solder the socket on the bottom you don’t risk re-creating the short.
Apologies for any inconvenience.