Ethernet keeps disconnecting

I'm curious about the timing of the problem for everyone on this thread.

In my case, I bought my Dell XPS 15 in November 2021. It came with Win 11 Home pre-installed. I immediately upgraded to Win 11 Pro.

From Nov 2021 to May 2022, my Ethernet worked flawlessly. Then, around May 28, the disconnection problems started out of the blue. The timing did not line up with any OS, software, or hardware changes. Also, no changes to my network setup at that time. The same setup that previously worked fine just started failing.

What about you? Did it happen right after upgrading to Win 11? Did it happen from the start on a new Win 11 machine? Did it work for a while and then mysteriously stop?

Mine started happening immediately because I just received the laptop in July and it came with Windows 11.

We haven't had an Windows 11 new from the box yet. But any user who has updated to Windows 11 is having issues, so we're rolling people back to 10 at the moment, or telling them to use WiFi.

I just want to report that my organization is having the same issue. We are using Ubiquiti Unifi switches and a Fortigate Firewall. Windows 10, Server 2012, Server 2016, Linux servers and workstations, etc do not seem to be experiencing this issue. It only seems to be Windows 11 machines and possibly only Windows 11 tablets/laptops that are connected to Ethernet via docking stations.

This seems to affect nearly all brands, Lenovo, Microsoft, HP, etc. We have one Beelink mini-PC with AMD Ryzen mobile hardware and a dedicated Ethernet port and it does not seem to be having the issue, which further leads me to believe that it's only affecting Windows 11 machines using Ethernet via a docking station.

Unfortunately eventvwr only seems to log that it's disconnecting with no indication as to why. The only clue I can come up with is that we get disconnection events on the uplink between our core switch and our firewall on certain VLANs. My department head thinks that this is causing a brief DNS failure which Windows 11 detects immediately and tries to workaround by failing over to wifi but sometimes the fail-over doesn't work and that leads to the service disruption. I haven't found any indications that this affects anything, DNS or otherwise. My theory is that the Unifi Controller shows disconnection events on certain VLANs because it sees the firewall as just another host and doesn't expect traffic on so many VLANs.

I've worked with Fortinet support on this, they had me run lots of tests but couldn't determine the cause. Which further leads me to believe that the VLAN disconnection events on the firewall switchport are a non-issue. I've also reached out on the Ubiquiti/Unifi community forums, but haven't received any replies.

This is the first place where I've found others who seem to be experiencing exactly the same issue as we are. So far this seems like a Windows 11/driver/docking station firmware issue. I hope that this thread will lead to someone figuring out what is going on here and finding a resolution.

I wasn't sure what to do so I purchased an adapter to plug in my ethernet cable directly rather than using the dock. We'll see if it works long-term but there seems to be improvement with my connectivity issues.