tvOS 13.3.1 (build 17K5792a) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2020-01-14T18:28:55Z. The update package is 85.46 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: f292e9f64c58ff2dfdd84ee81d76058873d76d65.zip.