https://www.theverge.com/circuitbreaker/2018/8/13/17683758/pixel-xl-android-9-pie-fast-charging-problems

As with any major software release, Google’s recent launch of Android 9.0 Pie hasn’t gone off without some early bugs and issues. The company just pushed out an Android Auto app update to get its in-car experience working nicely again with Pie, but owners of the original Pixel XL are having some troubles of their own.

Users are reporting that Android Pie has seemingly stopped their phone from fast charging when plugged into many chargers. Even Google’s own charger isn’t working as it should in some cases. Other Pixel XL owners say the bundled charger still functions properly and displays “charging rapidly,” but third-party USB-PD (power delivery) chargers no longer juice up the XL as quickly as they did pre-update. Android Police first documented the ongoing problem.