Moto G5S Plus has started to receive a new OTA update in US. The update brings June security patch and the latest stable Android Oreo 8.1.
Update also brings other features such as new multitasking features, more efficient notification controls, improved data saver and battery features, new power menu UI and Bluetooth improvements. You can also manually check for the update by heading to Settings -> About Phone -> System updates. Update will be rolled out in phases, it will take another couple of days to hit all the devices.