Hi Ivan,
Thank you for your reply.
For iOS:
The case I mentioned above is not easy to reproduce in iOS every time. But one of our users did get the screenshot:
I checked Charles log and found that, even though the ads displayed in right format, there is still one request failed with status code 400
every time. Below is the screenshot:

The
"/getconfig/pubsetting" always responses with error.
And as you required, the unit id for iOS is "
ca-app-pub-1182739567323523/4235275290".
And here's the implementation:
For Android:
The unit id is "ca-app-pub-1182739567323523/1694584894".
Later I will post the charles log and implementation from our Android team.
Regards,
Nestia