DFP Native ads not working on device



We are implementing DFP native ads in our app.
When the ad is delivered, it calculates the height of the ad and sets the iFrame height accordingly.

This works fine when testing with “ionic serve” in a browser, but when building to a device (Android and Iphone) the calculated height is always 0 (zero).

I have contacted DFP support, but their response is that they do not know anything about Cordova/ionic. When they test it in their own test apps, the banner works fine. So their conclusion is that it must be a problem with Cordova/ionic.

Any ideas?

I have set up a test app, so you can see the problem: