Sony Mobile has unusually released a very minor update for the Xperia XZ1 and XZ1 Compact handsets in some regions, moving the build number from 47.2.A.4.41 to version 47.2.A.4.45. T
he firmware remains with 1 December 2018 Android security patches, so it is likely that Sony added some other small bug fixes for the update. Strangely, the same update is not available for the Xperia XZ Premium, which normally follows the same build tree.