Are you sure that the banners are not visible in test mode? Because when I created a banner 1 week ago with the Admob account I created 2 years ago and selected the TestMode option in the project, the ads were appearing as "Test Ads". I created a new Admob account, everything seems fine but the banners are still not visible. It may be related to the v397.2 version, I don't know.
Hi. I didn't get my point across correctly.
ALL of Admob's test ads are displayed on the device. This is when you see the ad but it has a test mark on it. That's on a mobile device.
The banner is not displayed during the Construct3 preview, this is when you have a project open on your computer and you click run, only the banner is not displayed.