Wingers Swapping Positions?

Why do my wingers automatically swap positions to the opposite side during a game?

Have I accidently changed a setting to this or such?

Any help would be appreciated.

In the player instructions screen there is an option to swap position, it sounds like you have this selected.

To stop it doing this go to the players that are swapping sides, bring up their player instructions and check the swap positions it's down next to the man marking options (i think) and then on both players set it to none.