when you throttle down does the tendency to climb stop? If so it’s a thrust angle issue.
Bear in mind flat bottom wings do climb under power. But if it’s very noticeable it could be the thrust angle
so does the airplane not want to flair or slow down on approach? Could be the CG.
Is the airplane sensitive in pitch? The more you fly the worse it is? LOok at CG.
let us know what you find