iOS 13.3.1 (build 17D5044a) is an official Apple over-the-air update for the iPhone XS Max, released on 2020-01-14T18:21:05Z. The update package is 242.75 MB. This is a delta (partial) update that requires 13.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 335db204ec5eeaf4c3af72752716b3231983deb3.zip.