john Deere 240 skid steer no reverse left stick only

[JohnB21]

Hi I'm having an issue with my 240 skid steer. It has no reverse on the left stick. Everything else works as it should. The left hydrostat motor was rebuilt already. Forward works fine and so does the right control stick in both forward and reverse. Its only issue is reverse on the left side. What could cause this? It appears that everything is adjusted correctly.