Learn how to repair unhealthy animation when replace UIView top from taller to smaller measurement in swift XIB?

Hiya presently i am going through unhealthy conduct when replace my bottomsheetview from taller measurement to smaller measurement. When it comes from smaller to taller measurement, the animation works effectively. However on the reverse situation, the conduct grow to be the peak shrink upward not downward just like the video under

I’ve set the bottomview.backside to superview.backside equals 0, however why when the peak set to smaller measurement, it is going upward (not the highest half happening)?

The way in which resize the content material

extension BottomSheetViewController: ConfirmationDelegateBottom {
    public func resize(top: buttomHeightType){
    
        contentViewHeight.fixed = top.worth
        
            UIView.animate(withDuration: 0.3) {
                        self.view.layoutIfNeeded()
            }
    }
}