Dynamic links only working in Simulator, and NOT on actual device

Question

The dynamic links used to be working fine both on actual device, and also in the simulator. When I click on the link in the simulator (or pasting it in safari), I get redirected to the ".page.link" site where it says "open" - and clicking open opens the app perfectly. However, if I repeat the same steps on my actual device, I get redirected to the support url, and nothing happens (app doesn't open even though its installed on my phone).

This is my code in where I display a url

if let uid = Auth.auth().currentUser?.uid {
            guard let link = URL(string: "https://www.testapp.com/uid=" + uid) else {
                return
            }
            let dynamicLinksDomain = "testapp.page.link"
            let linkBuilder = DynamicLinkComponents(link: link, domain: dynamicLinksDomain)
            linkBuilder.iOSParameters = DynamicLinkIOSParameters(bundleID: "com.burgertralla.theGreat")
            linkBuilder.shorten { (url, _, _) in
                if let url = url {
                  self.shareTopLabel.text = url.absoluteString
                }
            }
        }

And this is my AppDelegate:

func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
        if let dynamicLink = DynamicLinks.dynamicLinks().dynamicLink(fromCustomSchemeURL: url) {
            self.handleIncomingDynamicLink(dynamicLink: dynamicLink)
            return true
        }
        return false
    }

    func application(_ application: UIApplication, continue userActivity: NSUserActivity, restorationHandler: @escaping ([Any]?) -> Void) -> Bool {
        if let incomingUrl = userActivity.webpageURL {
            let linkHandled = DynamicLinks.dynamicLinks().handleUniversalLink(incomingUrl, completion: { (dynamicLink, _) in
                if let dynamicLink = dynamicLink, let _ = dynamicLink.url {
                    self.handleIncomingDynamicLink(dynamicLink: dynamicLink)
                }
            })

            if linkHandled {
                return linkHandled
            }
        }
        return false
    }

    func handleIncomingDynamicLink(dynamicLink: DynamicLink) {
        guard let pathComponents = dynamicLink.url?.pathComponents else {
            return
        }
        for pathComponent in pathComponents {
            if pathComponent.contains("uid=") {
                let uid = pathComponent.drop(prefix: "uid=")
                Database.database().reference(withPath: "profile/" + uid).observeSingleEvent(of: .value) { (snapshot) in
                    if snapshot.exists(), var data = snapshot.value as? [String: Any] {
                        data["uid"] = snapshot.key
                        let userProfileVC = UIStoryboard(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "UserProfileViewController") as! UserProfileViewController
                        if let tabBarVc = self.window?.rootViewController as? UITabBarController {
                            tabBarVc.selectedIndex = 1
                            if let discoveryVC = tabBarVc.viewControllers?[1] as? UINavigationController {
                                userProfileVC.selectedUser = data
                                discoveryVC.pushViewController(userProfileVC, animated: true)
                            }
                        }
                    }
                }
            }
        }
    }

Do anyone have any clue on whats going on here?

Thanks for the help guys :)

EDIT : It does work on my iPhone with Chrome, however not with Safari. I don't know why...