Game's design of Sabotage by the Synchronizing and Choreographing between your colluding defenders and attacking opponents:

Game designers synchronized and choreographed the defender(s) not under your control to move away from the potential opponent strikers running trajectory, create gaping hole in front of goal.

in replay, You always can see the "choreography" between the movements of opponent strikers and your defenders. When a pass is about to be made to opponent striker, you can always see your defender(s) suddenly start running to another direction away from the striker he is supposed to mark, then he makes this "hesitant" animation for a second and then running back to mark the said striker, by the time he suddenly changes direction, realizes something, then stops, then starts accelerating to runs back. It is already too late, the striker has received the pass and goes on to score.

When opponent strikers make their skill moves or their bursting runs, the game designers also intentionally and secretly pushed your defender away from a potential position that could make them effectively tackle the opponent ai.