EDIT:
So according to this thread, this is a Google related change and not Nvidia?
In which case, similar to the banner issue from a previous update, you can get a different launcher (see comments for FLauncher) to avoid it
https://www.reddit.com/r/ShieldAndroidTV/comments/181vh4t/ads_at_full_screen/
You dodged a rocket lol. I have firetv which is android based. But I only have it Kodi. Roku is probably the best streaming. Unless you have a different smart platform on your TV such as LG or Samsung.