abody_sb3alil I don't know if I can help you with that. I'll just tell you that although I don't typically use secondary contain, I think that teammate behavior may have been slightly adjusted through an update. It's purpose seems to be to jockey and cut off some angles and not necessarily to crowd the ball. However, if I manually force the attacker towards the containing player, they can sometimes engage and make an attempt on the ball. As for the X button, it is best used for physical duels like seal-outs, and certain physical tackles depending on your game settings. I don't know exactly how you would be able to crowd the ball, so I hope someone who knows better than me will assist you if possible.
All the best to you!