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/
Same for me.
In the current version it was already advertising / recommending shows and movies too me I have no interest in. I just want my plex content and that’s it. A custom launcher is great for that.
Same here, one other improvement I would recommend is remapping the Netflix button to something less annoying/more useful in case you press it accidentally. If you have Hue lights, you could make it toggle your lights with this app for example.