https://www.theverge.com/2018/10/23/18013606/google-pixel-3-xl-photo-saving-bug-software-update

Google will fix an issue that caused some photos taken with Google Camera on the Pixel 3 and Pixel 3 XL to not properly save. A Google spokesperson provided this statement: “We will be rolling out a software update in the coming weeks to address the rare case of a photo not properly saving.”

The issue also affected a small number of Pixel 2 and Pixel 2 XL phones in addition to other Android devices like Samsung’s Galaxy phones, Moto Z and E models, and the Nexus 5X.