Question Ethernet Identifying/Disconnecting Every Few Seconds

Jul 6, 2020
Hello all,

I've had this build for a few months now and everything has been working fine until a week or so ago my computer was no longer detecting that the ethernet cord I had plugged in was there. Nothing physically changed from when I had last booted up so I suspect some kind of software issue.

I've already done a fair bit of troubleshooting including trying different ethernet cords (no luck, and also tried the cord I was using on another device which worked and was able to connect to the internet just fine), updating the network adapter drivers through the device manager, and updating my BIOS on my motherboard (ASUS TUF GAMING X570-PLUS).

After fiddling around a bit I noticed that when I first plug the ethernet cord in the light will blink briefly before going out, and then turn back on a few seconds later before turning off again. This is mirrored in the network and internet settings where an ethernet connection will pop up for a second as "Identifying" and then disappear quickly after, and this repeats itself over and over.
Further, I found that if I go into the properties of the network adapter through the device manager and change the "Speed & Duplex" to anything BUT Auto Negotiation or 1Gbps Full duplex I am able to get a stable connection (note that on other options such as 100 Mbps full duplex the connection will identify then disconnect a couple times before stabilizing). However this limits my network speed pretty drastically so it is undesirable compared to the wifi dongle I'm now using instead.

Some research Ive done suggests that this could be an issue with registry keys or windows but I'm not really sure how to go about fixing that without a full reinstall. If anyone has any ideas on how I could go about fixing this I would greatly appreciate it!