But the gameplay & AI is different in trial match and "my league" mode ("online mode"). "My league" is way faster, pacier and not that authentic like a real trial match.
It's the same if you play against the AI in trial mode or an event match against the AI, it feels different.
So I've the feeling that superstar AI in "my league" is easier than in trial match. Did you give it a try?
Some hints from my side playing fuma: don't play eFootball the "pes way", so don't focus just on passing around the ball. Pick a player that is a strong dribbler and then try to make small dribblings e.g. around your own axis. This will work often against superstar AI and you'll create some space.
Moreover somehow the crosses are more precise if you're playing fuma and using the early cross (LB+B or L1+circle). This will lead to more goals using a header

I'm using also the through pass rarely. Instead I'm just using the normal pass and aiming into the free space. This works also if you're in the opponents box, but it needs some practise, but works better than in PES 2020/2021.
For longer passes which could be also a through pass I'm often using super control to intercept the "programmed running line" - this works very often against the AI, the defenders are behaving sometimes weird.
Regarding the defense: stopping these through passes which were mentioned: switch to a player which is deeper (closer to your own goal) and let your teammates (AI) attack the player with the ball.
Maybe
this tutorial for "teammate press" helps.
(in general this tutorial is really useful to learn the new controls for defending since it has been changed compared to PES 2020)