Mobile SDK iOS: The chat message input box disappears after switching the app and coming back to the chat screen.

I've already tried the Zendesk demo app (https://developer.zendesk.com/documentation/zendesk-web-widget-sdks/getting_support_on_zendesk_mobile_sdks/#reproduce-the-issue-in-our-demo-app).

They reproduced the same issue as follows:

notificationId = NotificationCenter.default.addObserver(forName: UIApplication.didEnterBackgroundNotification,
object: nil,
queue: OperationQueue.main) { _ in
UIApplication.shared.keyWindow?.endEditing(true)
}

1. add the above code in func viewDidLoad() of Clickable links > MainViewController
2. run Clickable links in real device
3. click Initialize SDK to initialize
4. click Show Conversation to show chat screen, the input box is at the bottom of this screen
5. put the App to background
6. re-enter the App to foreground
7. the input box is hidden, the same issue happened

iOS SDK versions:
Zendesk (1.13.0):
- ZendeskSDKConversationKit (~> 1.10.0)
- ZendeskSDKCoreUtilities (~> 1.4.0)
- ZendeskSDKConversationKit (1.10.0):
- ZendeskSDKCoreUtilities (~> 1.4.0)
- ZendeskSDKFayeClient (~> 1.5.0)
- ZendeskSDKHTTPClient (~> 0.13.0)
- ZendeskSDKStorage (~> 0.8.0)
- ZendeskSDKCoreUtilities (1.4.0)
- ZendeskSDKFayeClient (1.5.0):
- ZendeskSDKLogger (~> 0.8.0)
- ZendeskSDKSocketClient (~> 1.5.0)
- ZendeskSDKHTTPClient (0.13.0):
- ZendeskSDKLogger (~> 0.8.0)
- ZendeskSDKLogger (0.8.0)
- ZendeskSDKMessaging (2.13.0):
- Zendesk (~> 1.13.0)
- ZendeskSDKConversationKit (~> 1.10.0)
- ZendeskSDKCoreUtilities (~> 1.4.0)
- ZendeskSDKUIComponents (~> 2.8.0)
- ZendeskSDKSocketClient (1.5.0):
- ZendeskSDKLogger (~> 0.8.0)
- ZendeskSDKStorage (0.8.0):
- ZendeskSDKLogger (~> 0.8.0)
- ZendeskSDKUIComponents (2.8.0)

We have enabled logging as follows according to https://developer.zendesk.com/documentation/zendesk-web-widget-sdks/sdks/ios/getting_started/#troubleshooting:

ZendeskSDKLogger.Logger.enabled = true
ZendeskSDKLogger.Logger.level = .debug

We have not seen any errors in the log.