Hello. I installed the Android 7.0 Nougat update on my phone a few weeks ago and ever since that time I have had persistent issues with my WiFi where it will either not stay connected while in use or go through normal connection speeds (40+ Mbps download) to crawling (0.34 Mbps download) when testing using the SpeedTest application. I can get these results within minutes of each other and without moving my phone from the place of testing. I never get results in the middle, it's either really fast or abominably slow. The first few days after the update, I killed my data plan because the WiFi was so awful. Since then I've had no choice but to use the throttled data speeds (which are often faster than my WiFi speeds now) or just deal with the WiFi connection being so bad. This has also been destroying the battery on my phone. I used to get an easy 16+ hour day out of my battery (off battery at 8am, no need to charge until midnight or later and that was usually still only around 20% remaining battery life). Since the update, my phone is below 50% battery by the mid-afternoon (during my work hours when I hardly touch my phone) and will be below 15% by 8pm, often completely draining and turning off by the time I normally go to bed. If it's the weekend and I'm not at work, I basically have to have my phone connected to a charger at all times. I've never had to plug in my phone to charge multiple times a day until this update.
As for my WiFi, it's not my router that's causing this issue. The problems I have been experiencing with my WiFi on my phone started the exact day of my update to Nougat. I have a multitude of devices connected through my router and none are experiencing any connectivity or speed issues. Only my Note5 is affected.
Also, most likely due to the connection being so bad with or without WiFi enabled, I am either unable to send a text message without rebooting my phone or I receive text messages hours later. The timestamp for the text on my phone will be for the time it was sent, but I don't get any notifications of a new message until several hours later. This also occurs with Facebook Messenger. Instagram has also been acting strangely since the update where it will either not give me any notifications whatsoever (and also refuse to refresh my feed or notification screens) or it will suddenly show me 15+ notification tiles on my lock screen from stuff that happened days ago. And if this happens, it will keep showing me the same old notifications over and over again (every hour or so) until I reboot my phone. I've had to reboot this phone more in the last few weeks than I have in the nearly 2 years that I've owned it.
I just remembered another one. My WiFi Calling is absolutely horrendous, and no wonder why if my connection speeds are so inconsistent. I've had to drop calls numerous times, disable my WiFi, and call back because I couldn't hear anything on the other end outside garbled noise. When I call back using my cellular connection, the person on the other side will usually tell me they couldn't hear me at all or it sounded like I was speaking from the bottom of a well.
Is there any way to fix any of this? This update has caused my phone to go from "I'll be able to use this thing for years" to "I want to snap you in half." It has been so frustrating and I've been holding onto hope that maybe there will be a hotfix or something and my phone will start to work correctly again, but I've seen nothing regarding that so far. Please help.