Why is the interstitial appearing in iOS in the upper-left corner and covering only 75% of the screen?
Generally, Interstitials appear on 75% of the screen in iOS, when they are created as a "bannerstitial", instead of a true "interstitial", or when they do not contain the correct dimensions according to Google's requirements. Below is the Google documentation explaining how to set up the Ad units in the Google DFP system.
According to the Google documentation, it is recommended to create the Interstitial Ad Units, including the following 4 dimensions:
Here is the Google DFP documentation that explains what the requirements are:
Create in-app interstitials - https://support.google.com/admanager/answer/4532115?hl=en
Creative templates - https://support.google.com/admanager/answer/1138308
Going through the documentation, you can see that Google recommend the following:
a) Add these same Asset sizes in the Ad unit inventory.
b) In the section "Delivery -> Line items":
i- Add a new "Creative" for each dimension of the Ad unit, by clicking on "System Defined Template" and filling it with the option "Mobile Interstitial with Auto-close (app)"
-> Then after, load the relevant File for this Ad Unit dimension.
This phase must be repeated for each Size in the inventory.
ii- Once you have finished configuring the Assets, you have to select: "Allow Scaling = Yes" + "Allow Stretching = Yes".
* Please remember that Google DFP is a system primarily for Android and that Google predominantly supports Android.
This means that "Scaling" and "Stretching" do not always work correctly on iOS.
In the event that the image appears centered but with a black border, this is in fact the correct behavior defined by Google for the product. It is not something that we can change on the Applicaster side, since it is programmed in the Google DFP SDK.
However, there is a Solution in the form of Custom Creatives.
Google allows you to create your own Custom Creatives of various sizes and add a Styling file type CSS, all Snippet of the code.
This allows you to render the Creatives, differently on each device.
I pass here the Google documentation explaining how to create the Custom Creatives:
Manage traffic for (Custom Creatives) custom creatives - https://support.google.com/admanager/answer/3180782?visit_id=636698403536930879-719775986&rd=1
Explanatory video with the steps of creating a DFP Interstitial Ad unit:
We have created a video (internal) where the steps for the creation of the interstitials are seen.
Basically what we have done here is to follow the steps that are in the Google DFP documentation, until the creation of an Ad Unit of an Interstitial:
[Of course this is NOT an official Google video and the actual configurations can vary and change according to Google's decisions. The video is more for you to see an example that we have created, and follow the steps with us]
Please read the documentation and see this short video that explains the steps one by one.