Update on my phone: 100% Death

(Degeneration -- Resets started 3 months ago; Bluetooth, Wifi died 3 months ago; 2.5 months ago Moto Services App and related apps started to bug out (Screen calibration, shake gimicks, sensors); extreme lose of signal every 2 minutes while making calls started 2 months ago; Software and heavy app bugs started 1 months ago (related to storage stability), Very low RAM 1 month ago, Screen with white bars and death pixels 5 days ago, Critical failure today (phone unable to boot, LCD screen burned out due to overcurrent [green and white flashes], battery still with charge) 

I'm sure most if not all of the phones experiencing battery drain will eventually die catastrofically if the user is extremely patient and relentlessly fixing issue after issue. Lack of Wifi, Bluetooth, and network connectivity as well as exesive heat and heavy battery drain are all sympthoms to the REAL core issue.

CORE ISSUE: Power management cycles (controlled by CPU) damaged by bad Nougat/Oreo port of Battery Saver features WITH the high risk introduced by dual charging (moto mod pack)

What does this mean eli5:

Your phone started to kill itself because Lenovo did not tell it how to charge/use battery properly.

Why did Lenovo forced you to update Android (even if they knew this could break your phone)?

Security compliance for other apps and Android support directly from google. Their hand was forced, but their implementation was laughable as an engineer and infurating as a customer. 

Basically, as a result, your CPU will send repeated power spikes to every important hardware part of your phone until they fry (Wifi Modem, RAM, Battery, Screen, Bluetooth chipset, SIM Modem).

What controls these spikes or what goes down first? Your apps do but mostly Moto apps used to control the phone and the framework of Android developed by Lenovo to be compatible with the Moto Z. The first thing that will go down is either your Bluetooth and Wifi or your Battery. Wifi and Bluetooth are controlled by the linux drivers though at least 2 methods. One linked to direct Android tools and another through Moto utilities. They are told to turn on and off untill they die or they drain the battery all together by constantly requesting overcharge. This is why you get excesive heating and your phone never appears to go into power saver mode when wifi is on. 

The Moto Z 2 and 3 are so inferior to the Moto Z that Lenovo probably ported the same framework developed for them for Oreo backwards into the Moto Z thinking that would cut the work. Then, they failed to add the complexity back and here we are. 

Shame. 

You can still make this right, Lenovo. I know what you did.

Sooo...NOBODY has said any of the suggestions helped...but this is marked as "Solved!  See the Solution!"?????  Really?  Not one person on here, or on the similar Verizon board, has said anything suggested by either tech support desks has helped.  Yet...you claim the problem is solved.  How is it solved if NOT ONE person has been helped, and MORE come daily to say they have the same problem that was caused by the UPDATE that you forced on the phones that WE OWN!??  We did not ask for this update...many of us rejected it...and you forced it on our phones anyway.  Now our phones don't work satisfactorily...and you have no answers that help.  Yet you say our problem is solved!!

Shame on you!!

Does anyone know if the same battery drain issue happens with jail broken phones?  Just wondering if it is inherit in the OS straight from Google or modifications that were done by Lenovo or the carrier.

I got the Oreo 8.1 update today and have installed it ...And have observed that major battery drain after update..Is there any fix for that...Before update my battery performance was good. .I have been  using moto g5 plus since last year I didn't face any issues but after update am facing these issue ...I am thinking  downgrade to  naught again...even wifi/ mobile data  is also not working properly .Please suggest .

I'm going to be more useful than the Motorola/Lenovo techs here.  After browsing online, I came across a few tips on how to fix this ridiculous battery drain issue.

The following FIXED THE BATTERY DRAIN ISSUE:

Disable an App called AppFlash (hidden system app, use "show system" option)

Not only disable it, "clear data" too

Next, 

Google Play Services app, go into app data usage and disable "background data" and also clear all data.

After I did those two things, my phone appears to be functioning as it was prior to the 7.1.1 update (no battery issues)

Hope this works for all of you too.

The solution is to get a new phone.

Verizon replaced mine. With a new/refurbed Moto Z. I don't understand why this one works with 8.1 and the upgrade didn't work on mine. Whatever. There's nothing you can do if it's not working.

Hit the 3 dots on the top left of the screen.  Check out the screen shot

It won't matter.   The power spikes will kill it. On mine, taking 3 photos would shut the phone off.