Sony Mobile has released a new firmware update for the Xperia XZ1 and XZ1 Compact series, upgrading the build number from 47.1.A.2.374 to 47.1.A.5.51. This new firmware build now brings the Xperia XZ1 devices into the same software branch as the Xperia XZ Premium, which recently launched with the same build.
The latest Android 8.0.0 Oreo update adds the camera distortion fix option, which can be found in the camera settings, along with the latest 1 November Android security patch. It should start rolling out across all regions over the coming days, although timing will vary by region.
Thanks Makis and Toomas!