[One (M9) Q&A, Help & Troubleshooting] TheMegosh:
Hey folks, I've been having problems with my M9 for over a week and hope someone more knowledgeable can resolve this with me!

History

Firstly, I purchased this phone from Wind Mobile in Canada. Almost instantly I S-Off and migrated to Venom 1.9~ (updating along the way) where things worked flawlessly up until last week (the Venom 3.0.0 update). Along the way I've updated my firmware frequently as they have come out following Sneakyghost's Thread and the associated Google Spreadsheet. For all of the tests I am about 10ft away from my router and am always on the 2.4GHz frequency. Also worth noting that I have tested it on 5GHz and 3 other separate routers, without success. Since encountering this issue I have verified all MD5 sums of all downloads. I have a Venom 2.3.1 nandroid where this issue does not occur and rely entirely on that whenever I'm not flashing and trying to resolve this (so it is not a physical issue!).

The Issue

After updating to any ROM running Android 5.1 (with a strange exception of upgrading from venom 2.3.0 to 2.3.1 where it occurred): The Wifi on the device will not maintain a connection. At most, it may last 5 seconds. At that point, the statusbar wifi icon will hide and the data icon will take over. Some times the wifi drops so quickly, that the data icon will never disappear before the wifi drops along with its icon. If I bring the main Wifi settings menu up, I will see the entire list of saved wifi networks appear and disappear at the same time wifi is lost (almost as if it were scanning for available networks and drops whenever it does. Just a guess). If the Wifi Status window is opened (displaying specific signal strength, frequency, IP, etc), I will see the strength maintain "Excellent" while the IP address disappears whenever the connection drops. It has been suggested that wifi networks with a "space" in the SSID can cause issues with Android and other devices. Below I will post logcats of various tests, both with and without spaces in the SSID and indicate as such (doesn't seem to affect the issue).

Current Information

I have tried various firmwares that have seemed to have no affect on the results: (associated DownloadMode screenshots: one and two)

1.40.401.8

2.7.401.1 (current, what all logcats were run on)

2.8.617.4

The Logcats

http://pastebin.com/AAG0smLS - Running Venom 3.0.0 along with all of my apps - SSID: "Rose 3"

https://drive.google.com/file/d/0B00EvrpIDE-MdmNseXp4RXJ0UkU/view?usp=sharing - ARHD10 full wipe - SSID: "Rose_3"

https://drive.google.com/file/d/0B00EvrpIDE-MTHVPVTVFT195QWs/view?usp=sharing - Venom3.0.0 full wipe - SSID: "Rose_3"

more to come...

I would like to thank you all for taking the time to read this and hope that your contributions will help me come to some resolution! If there is anything you would like me to include or try, please let me know as I am open to anything.

I would also like to take the time to thank Nandroids for being awesome and for being the only thing that allows me to continue to use my phone. :angel:

Edit 1

Moments after posting, ARHD 8.1 (Android 5.0.1) finished optimizing and the issue does not occur! Since it also works on Venom 2.3.1 (Android 5.0.1) I can come to the conclusion that it is because of Android 5.1. Now if only I could figure out why....