Wireless (WiFi) transfers between Win10 Desktop and phone/devices slow. Network speeds are fine

What's happening guys.

This is quite annoying. I'm running Win10 pro on my main desktop. It houses a bunch of servers (Plex, NZB, nginx, SQL, etc). File transfers from outside IPs are flying past w/ 100Mbps upload from my desktop. Local transfers over non-SMB protocols work great too. Local files over nginx or Plex are super fast, maxing out WiFi at over 400Mbps.

However, as soon as I try to connect locally via SMB and transfer files from within my intranet, speeds are awful, maxing at 300kb/s if I'm lucky. This is quite annoying as I transfer files like this quite often between different devices and their speeds are fine (laptop > desktop is fine. Desktop > laptop is terrible; Laptop > phone is fine, Phone > Laptop is fine; Desktop > Phone is terrible, Phone > Desktop is fine)

Again, only happening through LAN/SMB connections, not via other protocols.

Anyone experience this before? The network is more than fine, it's running on a RB2011 w/ the latest rOS. Everything is on either a 5Ghz network or via a gigabit connection. Wireless devices are next to an AP, longest ethernet run I have is around 40ft to my 3rd floor AP.

I went through this: http://answers.microsoft.com/en-us/windows/forum/windows_7-networking/very-slow-200kbsec-file-copy-between-win7-machines/b8736b1b-0a91-4567-ba33-215084ffc906 and http://answers.microsoft.com/en-us/windows/forum/windows8_1-networking/very-slow-transfer-speed-between-2-computers-in/514c496c-c350-45bf-8486-3b68c2144812 but to no avail.