Target window settings for app ads using AdMob SDK and DFP premium

We are launching our first iPad app ad since integrating the AdMob SDK on DFP premium. We cannot figure out how to designate target window settings. Sometimes, our test ad opens in the native device browser and other times, it opens in-app. We have been unable to identify why the click through functionality differs. Our mobile engineers and Google support have not proved very helpful. If anyone has knowledge on this subject, I would really appreciate some help.