I’ve seen this bug since the update to glass, but only on one of my AppleTVs (4K).
It only occurs on the Favorites bar, where I can see what appears to be the placeholder boxes for the art. You can see the bottom line more clearly. Doesn’t occur in any of the other screens or sections and it shows on normal or true dark mode.
Diagnostic Code: T2JR5
Just curious, what gen ATV 4K?
I had this happen as well, but after updating to TvOS to 26.2 beta 2 it went away, latest gen Apple TV 4K hooked up to 1080p tv, at this time my other Apple TV didn’t show this and was hooked up to my 4K oled.
3rd Gen (A2737).
Yes, it only happens on the AppleTV 4K connected to an older 1080p LG Tv.
Yes, mine was an LG 1080p as well it happened too. But it’s fixed in the latest Apple beta and latest Infuse.
Thanks for confirming this has been fixed in tvOS 26.2 (beta). 
Seems it’s not isolated to Infuse. I was able to replicate the issue with any App pinned to the top row which shows landscape preview photos. Even the AppleTV App.
Model: A2737 (4K Gen 3) | 1080p SDR (59.94Hz)
