Same issue. Unfortunately WKWebView only fires its functions when a full page load happens.
So what we have to do instead is use Key Value Observing on the WebKit.url property.
Looks something like this:
import AVFoundation
import UIKit
import WebKit
import MediaPlayer
class ViewController: UIViewController, WKNavigationDelegate {
  @IBOutlet weak var webView: WKWebView!
  override func viewDidLoad() {
    super.viewDidLoad()
    webView.navigationDelegate = self
    self.webView.addObserver(self, forKeyPath: "URL", options: .new, context: nil)
    self.webView.addObserver(self, forKeyPath: "estimatedProgress", options: .new, context: nil)
    self.webView.load(URLRequest(url: "https://google.com"))
  }
  override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
    if keyPath == #keyPath(WKWebView.url) {
      print("### URL:", self.webView.url!)
    }
    if keyPath == #keyPath(WKWebView.estimatedProgress) {
      // When page load finishes. Should work on each page reload.
      if (self.webView.estimatedProgress == 1) {
        print("### EP:", self.webView.estimatedProgress)
      }
    }
  }
Each additional navigation in the wkWebkitView should cause a new combo of "### URL" and "### EP" to fire off.