Struggling with my 9yo and my 6yo

[F246]

I have 2 boys, 9 yr old and 6 yr old.

9 yr old I've always had a problem with him being jealous of his brother and constantly fighting with him. Being rude to him for no reason. Picking on him etc.

Recently he's started to have a lot of attitude towards me and his dad. Answering back and not listening to us on simple matters, like brush your teeth or get to bed.
Seems the more we tell him to stop doing something the more he enjoys annoying us.
Punishment seems to make him worse and he doesnt show any remorse.

However at school he gets the best reports and all the teachers are constantly praising him and his attitude and politeness.

The 6 yr old was always different to the 9 yr old. Always listening, never Answering back. Never rude, but recently, he's also started with the attitude and tantrums. He tends to hit his brother a lot. And he has full blown tantrums.
Punishment works with him, and he shows remorse.

I've tried family therapy.

Nothing seems to be working.

Any suggestions on how to deal with the 9 yr old mainly?

What have you tried so far? My children are smaller, but I've seen from my nephews that preteens can be blooming awful to their parents. Have you heard of calmer, happier easier parenting? It's a book and an audiobook. Has.a lot in there about giving attention to the behaviours you wish to see rather than rewarding other behaviours with your time and energy. Also has several techniques in there for helping NT children act with autonomy and encourage a happy household.

Siblings without rivalry is another one I'd recommend, and the 'how to talk so kids will listen' series.

I certainly found with ds3 the more 'cross' we got and the more 'punishments' he had the worse he got. We found the 'Easier, Calmer, Happier parenting book' really useful too and also the 'how to talk' books great. We found that lots of listening, empathising, and rewarding made a huge difference.