Arrow not showing on top of UITextField when rightview is set

Hi,

I'm having this issue as shown below whereby the pop tip will not have an arrow. Below is my sample code:
```swift
override func viewDidLoad() {
super.viewDidLoad()

self.textField.rightView = self.setupErrorToolTip()
}

func setupErrorToolTip() -> UIView {
let errorButton = UIButton(frame: CGRect(x:0, y:0, width: 20, height: 20))
errorButton.addTarget(self, action: #selector(toolTipButtonAction), for: .touchUpInside)
errorButton.tag = 1
errorButton.setTitle("!", for: .normal)
errorButton.setTitleColor(.white, for: .normal)
errorButton.titleLabel?.font = UIFont.systemFont(ofSize: 13, weight: .semibold)
errorButton.backgroundColor = UIColor.red
errorButton.layer.cornerRadius = errorButton.bounds.width/2

// create the view that would act as the padding
let rightView = UIView(frame: CGRect(
x: 0, y: 0, width: 25, height: 25))
rightView.contentMode = .center
rightView.addSubview(errorButton)

return rightView
}

@objc func toolTipButtonAction(sender:UIButton) {
let popTip = PopTip()
popTip.actionAnimation = .float(offsetX: 0, offsetY: 8)
popTip.show(text: "Hey! Listen!", direction: .up, maxWidth: 200, in: sender, from: view.frame)
}
```