We're in that awkward phase of the Android upgrade cycle, when customers want nothing more than the latest release of the OS on their phones... but manufacturers and carriers are still slowly, slowly making their way through the backlog of updates from over a year ago. So it is with the ZMAX 2, a big-screen budget ZTE phone offered on AT&T starting in September of 2015. Today AT&T is sending out the Marshmallow update that probably should have come at least a year ago. Hey, don't knock it - a lot of budget phones don't ever get upgraded at all.
The ZMAX 2 started on Android 5.1, and today's over-the-air update brings it up to Marshmallow 6.0.1 with the November 1st security patch. According to AT&T's customer support page, there aren't any significant changes outside the core OS upgrade and the security patch in build Z958V1.0.0B24. The download is a hefty 1.1GB - you might need to clear up some space on your phone, since the ZMAX 2 has only 16GB of local storage. As always, any root-level modifications of the software will cause the update to fail, so you may need to look for a stock build if you've done any tinkering.
AT&T stages its rollouts, so don't be surprised if it takes up to a week for the OTA notification to appear on your phone. And when can you expect to see Nougat on the ZMAX 2? Let's just say I wouldn't hold my breath.
- AT&T Support