Samsung has started bringing One UI 3.1.1 features to One UI 3.1, its OS for smartphones. Apparently, One UI 3.1 now has faster animations, camera app performance improvements and new processing speed options under Device Care settings, among other changes.
https://www.notebookcheck.net/Samsung-begins-rolling-out-One-UI-3-1-1-features-to-devices-starting-with-the-Galaxy-S21-series.556940.0.html