Swift：UIStackView内UITextField无法点击选中问题求助

我知道这个问题已有相关提问，但现有答案都解决不了我的问题。我在UIScrollView里放置了若干UITextField，视图布局完全正常，但无论如何操作，这些UITextField都无法通过点击选中。我有其他采用相同方式实现的带UITextField的视图均能正常工作，目前毫无头绪。

我的ScrollView代码：

let scrollView = UIScrollView()
scrollView.alwaysBounceVertical = true
scrollView.translatesAutoresizingMaskIntoConstraints = false
scrollView.showsHorizontalScrollIndicator = false

ScrollView内首先是一个ContentView（可能冗余，但我一直如此实现），它铺满ScrollView。ContentView内是垂直方向的UIStackView，所有内容都放在这个栈里。比如以下是包含标题、UITextField和错误标签的TextField栈代码：

//First Name Field
let firstNameStack = UIStackView()
firstNameStack.axis = .vertical
firstNameStack.spacing = 5
firstNameStack.translatesAutoresizingMaskIntoConstraints = false
    
firstNameTextFieldTitle.text = "firstName"
firstNameTextFieldTitle.textColor = colors.justWhite
firstNameTextFieldTitle.font = UIFont(name: "Montserrat-SemiBold", size: 14)
firstNameTextFieldTitle.textAlignment = .left
firstNameTextFieldTitle.translatesAutoresizingMaskIntoConstraints = false
    
firstNameTextField.textColor = colors.justWhite
firstNameTextField.backgroundColor = colors.lightyLightGray
firstNameTextField.attributedPlaceholder = NSAttributedString(string: "first name".localized, attributes: [NSAttributedString.Key.foregroundColor: UIColor.white]) //ID12
firstNameTextField.font =  UIFont.init(name: "montserrat", size: 18)
firstNameTextField.autocorrectionType = .no
firstNameTextField.textAlignment = .left
firstNameTextField.layer.cornerRadius = 5
firstNameTextField.clipsToBounds = true
firstNameTextField.setLeftPaddingPoints(10)
firstNameTextField.setRightPaddingPoints(10)
firstNameTextField.keyboardType = .default
firstNameTextField.addTarget(self, action: #selector(textFieldDidChange(_:)), for: .editingChanged)
firstNameTextField.translatesAutoresizingMaskIntoConstraints = false
firstNameTextField.delegate = self
    
firstNameTextFieldError.textColor = colors.errorRed
firstNameTextFieldError.textAlignment = .left
firstNameTextFieldError.font =  UIFont(name: "Montserrat-SemiBold", size: 14)
firstNameTextFieldError.translatesAutoresizingMaskIntoConstraints = false

firstNameStack.addArrangedSubview(firstNameTextFieldTitle)
firstNameStack.addArrangedSubview(firstNameTextField)
firstNameStack.addArrangedSubview(firstNameTextFieldError)

视图布局完全正常，我可以通过becomeFirstResponder()唤起键盘，但点击UITextField毫无反应。我肯定忽略了某个简单的点。

我已添加用于收起键盘的代理，并且为确保无误，添加了以下代码：

func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool{
    return true
}

请问问题出在哪里？期待相关建议。

内容的提问来源于stack exchange，提问作者Jan L