If am playing Left - Right, and i have a custom play that is for running on the LH side the result is players running on the top of the screen - as would be expected.

Once i change sides (R-L play now) and run the same custom play my players line up as normal but instead of running the play to the LH (bottom of screen) they run it to the RH (top of screen). Given the LOS setup was focused to protect the LH channel the results are as one would expect (i get smashed).