Many users of the device have started receiving an update which is still based on the Android 9 pie beta.
The latest Android pie beta brings September security patch among a few other improvements and new system navigation, settings menu and notifications, adaptive battery power prioritization for most commonly used apps, adaptive and optimized brightness levels, and predictive application actions.
The Nokia 7 Plus users are getting the Android security patch for the month of September 2018 and build number v3.190. The update size is 1481 MB.
Make sure your device have enough battery and storage of this update.