https://wccftech.com/diablo-iii-xbox-series-x-patch-4k/

A new Diablo III Xbox Series X patch is finally being deployed, fixing the game's resolution on Microsoft's next-gen console.

Blizzard's most recent Diablo release on consoles. Diablo III, runs via backward compatibility on Xbox Series X|S, and while the Xbox One X managed to upscale the game to 4K resolution, a bug prevented the game from doing the same on the Series X. To date, the game was locked at 1080p resolution on Microsoft's powerhouse, and as promised by Blizzard back in February of this year, a fix is now being released.