Undo/redo image progress

Question

I have a functionality that changes the picture, and there are two cancel/return buttons i wrote 3 functions for this add undo redo The problem is that when I press 2 times undo and then redo, my image redo is two steps forward

My code

 public var undoHistory: [UIImage] = []
public var redoHistory: [UIImage] = []

public func undoImage() -> UIImage? {
    guard !(undoHistory.count == 1) else {
        return undoHistory.last
    }
    
    if let lastImage = undoHistory.last {
        redoHistory.append(lastImage)
        undoHistory.removeLast()
    }
    return undoHistory.last
}

public func addImageToHistory(_ image: UIImage) {
    undoHistory.append(image)

    guard !redoHistory.isEmpty else {
        return
    }
    redoHistory.removeAll()
}

public func redoImage() -> UIImage? {
    guard !(redoHistory.count == 1) else {
        return redoHistory.last
    }
    
    if let lastImage = redoHistory.last {
        redoHistory.removeLast()
        undoHistory.append(lastImage)
    }
    return redoHistory.last
}