[Android Q&A, Help & Troubleshooting] playbacktri:
Backstory (skim through if you don't care to read):

Friday morning I woke up to find my phone was off. I had fallen asleep watching netflix the night before.

Hit the power button, nothing. Checked power plug, different cable, etc. Nothing seemed to turn it on.

Eventually found after jumping online that volume down + power would soft reset the phone.

That worked, phone goes to samsung logo and sits there. I reboot it a few times and it finally comes up. Stays on for 1-2 minutes then restarts on its own.

Basic search online shows to wipe the cache partition, I do that. Phone boots up ok, lasts about 5 minutes then reboots on its own.

I get all my data backed up (in between reboots) and decide to factory data/wipe via the menu ( volume up, bixby, power if I remember now)

After that...phone starts up as if new and I'm going through the setup. While going through the setup, phone reboots on its own.

I make it again halfway through the setup, and it reboots again. I can't get through setup of the phone at this point.

I repeat a few times of wiping cache, factory data reset.

Now the phone hangs on the Samsung screen and just boot loops. I go ahead and poke around online some more and download Odin plus a painstaking 24 hour download of the stock firmware for the SM-N950U1 (XAA) (Unlocked) Note 8 firmware, then proceed to run through Odin hoping that I can go ahead and just reflash the phone and basically re-install the OS to factory specs.

Low and behold, FAIL on the flash from Odin, it hangs on system.img.ext4 after about 5 minutes of running, says FAILED (auth) in Odin, and on the phone screen it says "Secure Check Fail : system"

Also, now when I boot into Download mode, I hit Volume Up for Continue and it says that an error has accured and to replace or re-install via Smart Switch (which I tried doing but can't get it to work, it says my device is not supported once I connect it)

Lastly, just turnign on the phone normally trying to boot up, it just loads a blue screen that says "Please re-install the factory image" or something to that effect.

I know this is long, but is there anything I can do to get this to take the stock firmware again? I can still connect to Odin and it will try to run through a process, it just fails every time.

Is there some special combination of Odin, USB drivers and firmware that might work? I keep reading that these phones are tricky and I've tried every cable and USB port that I can on my computer, reading that it could be as simple as that.

Anyways, I'm at a loss...any help would be appreciated. I know this was a long read.

Phone info -

Galaxy Note 8 - Model SM-N950U1 ZKAX (XAA based on Downloader info display)

Bought Unlocked from Samsung in October of 2017, have installed all OTA updates as they've come in. No other modding or messing around on this phone. I have rooted many phones in my time but haven't in a couple years.

Odin 3.13.1

Downloaded file was SM-N950U1_1_20190306182853_ecpwgsj7rn_fac.zip, 3.6 gigs, was supposed to be for XAA Unlocked Note 8 as of July of 2019, I'm assuming latest update?

I am update to date on my OTA updates, I an unlocked phone but on the Verizon network. I'm reading that I have to flash my phone with whatever build my phone was on, ie..not too new or too old, correct? Maybe the build I downloaded was too new? To my knowledge, I have no way of finding out what build I was on at this point...

Error report from Odin: