Windows 10: Realtek ethernet adapter refusing to be/stay on Gigabit

Hey TenForums, long time no see!

Basically, I've been having this weird issue for the past couple of days that has driven me to the point where I'm almost pulling my hair out. The issue is that my Realtek network adapter (the RTL8111H) will not stay, or even be on gigabit speeds. I have no idea what's causing this because the RTL8111H supports up to 2.5Gbps, the cable I'm using is a brand new CAT6 one and my router has CAT5e ports.

I've spent countless hours trying to debug this by messing around with the duplex settings with almost no success. Even though that's case, I actually did "succeed" during two occasions.

During the first, I got gigabit running for around 10 seconds, until it disconnected and went back to 100Mbps.

During the second, I had a much bigger success where I was able to get gigabit running until I restarted my machine. What I did then was to try other cables to see if my CAT6 was faulty and they did indeed give me gigabit speeds. I decided after that to plug in my CAT6 one and to my surprise it worked perfectly, until I rebooted that is.

It is worth mentioning that Auto Disable Gigabit, Gigabit Lite, EEE/Advanced EEE and Green Ethernet are all turned off. Duplex is set to 1.0Gbps Full and I'm running the latest drivers from my motherboard manufacturers website.

This has been really frustrating for me since I just got a network upgrade and I'm only getting 1/4 of the speed and on top of that, I have no idea what the culprit can be. I thank you for any replies in advance!

:)

 

Realtek Ethernet Drivers WTH?

Realtek RTL8168/8111 PCI-E Gigabit Ethernet Adapter (PHY: Realtek RTL8211/8212) Onboard

 

Intel Gigabit Ethernet better than onboard RealTek RTL8111E Gigabit Ethernet?

i am wondering if a Dedicated Intel Gigabit Ethernet will be better when i game online, surf and download and upload than the onboard RealTek RTL8111E on my ECS P67H2-A V1.1?

if yes, i have been looking at these PCI and PCI-Express Gigabit ethernet cards ^^;

Intel D33745 PCI-Express x1





Intel Pro/1000 MT Desktop Adapter- PCI Gigabit





Intel PRO/1000 PT Dual-Port-Server-Adapter PCI-Express x4

 

Windows 10 Pro Upgrade Breaks Realtek PCIe Gigabit Ethernet Adapter forcing 100Mbps instead 1Gbps

Two dead links unfortunately.

AS was stated in my original post, the drivers don't seem to be the issue, the issue is with Windows 10 and RealTek PCIe Adapters. I have gone through every available driver for that RealTek PCIe Gigabit Adapter, and still ALL Gigabit networks I plug into
both computers display "100 Mbps" instead of "1 Gbps"