The Samsung Galaxy A20 unit, locked in the US Xfinity Mobile network, received an Android 11-based One UI 3.1 update earlier this month. Currently, it is the unlocked model that is tasting the latest version of Android in the United States.
In addition to the usual Android 11 and One UI 3.1 features, the update comes with the August 2021 Android security patch. The firmware version is A205U1UEU9CUH3 and should reach all unlocked units in the US within a few weeks.
However, if you don’t want to wait for the update notification to pop up on your Galaxy A20, go to your Galaxy A20 and check for updates manually. Configuration >> >> Software update menu.