Help! 9 year old step son *parenting*

Hello, I’ve been having trouble with my step son. Well, my SO, me and his mom. I just want to clarify that we co parent great and are friends so it’s not like I’m overstepping or parenting when I’m not supposed to we all have the same problem with my step son so here it is- the past year he has started to lie but ALL the time and about everything. He manipulates us in the way of he will complain and tell a complete sad story on how his mom is terrible and he will do the same with her and everyone else around him. When he doesn’t get his way, all hell breaks loose. He doesn’t like his parents, parenting. He thinks he should do what he want, when he wants. Any punishment doesn’t work, if we confiscate electronics, he just acts out worse and that’s our main issue, the only interest he has is being on games. ALL day, he doesn’t play outside, he’s rude to everyone while he’s on his games, he just becomes nasty. He’s been in therapy and they cleared him but even when he was in therapy, his behaviour was just as bad if not worse because he would just lie to the therapist. He absolutely despises that his mom, dad and I all co parent and are friendly, he makes it his goal to pin us on one another but it never works. I just don’t know what to do, he’s so awful to us. Like, what gives?