OnePlus is working on its promise to deliver Pie on its older phones. Some OnePlus 5 and OnePlus 5T users have just started beta testing Hydrogen OS 9.0, the software used in China (as opposed to the Oxygen OS used abroad).
The change log promises a new UI. The 5T is also getting Android Pie’s full screen touch gestures (the 5 has hardware keys under the screen).
The handling of background apps has been revamped to deliver a smoother experience. The caller ID of the phone app has been improved and there’s a way to set a default SIM for dialing a given contact or group.