YouTube Premium still shows ads

I have had a YouTube Premium subscription, purchased on iPad Pro, for a year. It worked fine until a week ago, when I cracked my screen (unknown how) and had the device replaced under Apple Care.

Now, on the new device, the YouTube Premium app still shows up as Paid For and active. But the app behaves as if I do not have premium, and shows ads with a dismal frequency before, during and after trying to watch a video.

Anyone have a clue as to why this happened and how to fix it? My efforts to communicate with Google have been hopeless…one thing they’re not is customer friendly. Thanks in advance if you can help.