Button animation issue

Hey guys. I've created that function to animate my button:

Code Block private func animateButtonView(_ viewToAnimate: UIView) {
        UIView.animate(withDuration: 0.2, animations: {viewToAnimate.alpha = 0}) { [weak self] (true) in
            guard let self = self else { return }
            switch true {
            case true:
                DispatchQueue.main.async { self.addToFavoritesButton.setImage(SFSymbolsAsImg.checkmark, for: .normal) }
                UIView.animate(withDuration: 0.2, animations: {viewToAnimate.alpha = 1} )
            case false:
                return
            }
        }
    }

Code Block
private func animateButtonView(_ viewToAnimate: UIView) {
UIView.animate(withDuration: 0.2, animations: {viewToAnimate.alpha = 0}) { [weak self] (true) in
guard let self = self else { return }
switch true {
case true:
DispatchQueue.main.async { self.addToFavoritesButton.setImage(SFSymbolsAsImg.checkmark, for: .normal) }

UIView.animate(withDuration: 0.2, animations: {viewToAnimate.alpha = 1} )
case false:
return
}
}
}

But the problem is that animation does not finish. Alpha stays at around probably 85% from what I can see. Any help explaining what is wrong with this code will be appreciated! Many thanks.