With defence it is tricky - But it should be.
Defensive AI i am happy not to be doing a lot. But if you play patient and not too erratic they will position themselves.
Part of the key is drag midfielders back as soon as you lose the ball. You can apply 2nd man press but little at a time otherwise positions will get vacated. The best players will exploit that.
Double tapping up and pushing them back towards there half can help. But you have to be careful as it is risk vs reward.
Yes. This year you can win the ball back by running and rubbing up against opponents.
Don't be afraid to you the hard tackle if desperate.
Jockey and be careful. You have to be quick at switching around BUT only try and control CBs if confident. As weird as it sounds.
And last off. Just keep playing.
Oh, and also... how unstable is your connection? Who's your ISP and what is your latency usually?