I had a similar problem with my trainer. Overpowered it and it took the better part of 10 flights to get it sorted out.

I do prefer to stick to the recommended engine range on new models now.

I also had to decrease the wing incidence (lift the trailing edge), add more donwthrust and right thrust and then ultimately had tp trim it for 1/2 throttle flight and used a mix to add elevator beyond that setting.