ZTE, a few days ago, finally released Android Oreo for the Axon 7. The update is an Android 8.0 one that also doubles up as the July security patch, both of which are only the first in a long line of things wrong with the OS update.
https://www.notebookcheck.net/The-ZTE-Axon-7-finally-receives-Android-Oreo-but-it-s-a-mess.338822.0.html