https://wccftech.com/today-in-android-motorola-tests-out-oreo-8-1-for-moto-g5s-plus-and-more/

The Moto G5S Plus was released back in 2017 at a time when people were expecting the Moto G6 to hit the shelves. The device was an incremental upgrade over its predecessor, the Moto G5, sporting a dual-camera setup and a larger screen. Now, why Lenovorola released a successor to a perfectly good phone is something we still don’t understand, but that discussion is for another day. The company has received some flak for their flaky Android update roadmap, with several of their devices yet to receive even a single major update.

The Moto G5S Plus isn’t on that list and should ideally have been running Oreo by now and the update was rolled out in February this year in Australia and New Zealand. However, we’re yet to see a Moto G5S Plus that’s running Oreo, so its likely that the rollout was suspended at some point.