ROG Strix X299-XE Gaming LAN port dying?

[FaaR]

I bought this motherboard back in september 2017 IIRC, and the LAN port was kind of wonky from day one. I wouldn't get more than 60-ish Mbit/s through a web browser, either downloading files from a server or running an internet speed test type benchmark, but standalone downloaders could get the full bandwidth of my cable connection (200Mbit/s at the time.) That included battle.net desktop app and Steam client.

Funny thing was, it didn't matter which browser I tried (Chrome, MS Edge; both gave exactly the same - bad - result) if I connected through my router, or plugged the network cable directly into my cable modem. Also did not matter which cable I used, or if I used windows default driver or one downloaded from Intel. Also, my old PC (using some ROG Haswell mobo, don't recall which model exactly right now), using exact same cables, same Windows 10 version, and the cruddy Realtek LAN adapter included on the motherboard gave full bandwidth on browser speed test.

I ran Intel's diagnostic utility for the Intel LAN adapter on my new motherboard, and it said all of the cables I tried were "excellent quality".

It was kinda annoying, but I didn't bother to mess with the LAN issues because the PC worked well otherwise, and 60Mbit/s is still pretty fast (unless you want to download something REALLY big.) However, the port has been slowing down gradually, and a speed test now gives only about 5.5Mbit/s. (!!!) Which is...NOT acceptable! Downloading graphics card drivers for example at that speed takes like 15-20 minutes, which makes me feel like I'm back in the bad old days of dial-up internet connections!

Steam also downloads slower these days, instead of hitting 20+ MB/s like it did in the past (or 30-35MB/s like my connection is supposed to give nowadays) I get less than 14MB/s. Then again, maybe Steam is simply cheapskating on the server bandwidth like with everything else they do these days. *shrug* Might not mean much; I know.

So all in all, not sure what's going on here. Any assistance appreciated. I've been thinking about nuking the windows install and starting over from scratch, but the thing is, I started over from scratch last time also and got bad performance right out of the box for whatever reason. So it could very well happen again, since I don't know what caused it the first time around, and then I would have to re-download/install and set everything up the way I want it all over again, which would be a real pain in the you know what.

Again, any insights here much appreciated. Thanks in advance!

[G75rog]

I disabled the on-board port and installed a 10Gb card. Easier than fighting a flaky port.

[FaaR]

I disabled the on-board port and installed a 10Gb card. Easier than fighting a flaky port.

Yeah, except I have no available PCIe slots... I have dual 2.5-slot GPUs, so all other slots are blocked, sadly. No wish to go watercooling either, by the way.