Yes I installed that driver and the other drivers from the U2422HE support page. I also did Dell Update, which had a couple additional updates available. The monitor already had the latest firmware on it.

The LEDs are blinking green and solid orange.

Did you install the U2422HE Realtek Ethernet controller driver on every XPS 15?

When the RJ45 Ethernet cable is connected to the U2422HE Ethernet port, what color are the LEDs? See page 31 in the online U2422HE User's Guide =

I just found an old USB to Ethernet adapter I had laying around. Plugging that into the monitor via USB then connecting the same Ethernet cord to it works just fine. It's only the internal Ethernet port of the monitor that's not working.

U2422HE Right LED = Solid amber orange = 1000 Mbps
U2422HE Left LED = Green blinking = Activity on the port

But of those state the Ethernet is connected?

Yes, the Ethernet link seems to be fine. I can see the dock on my network controller as "Generic Laptop."

With the Ethernet connection connected to the U2422HE's RJ45 Device Manager reports:

When the USB to Ethernet adapter is disconnected and the RJ45 is connected directly to the U2422HE, what does the Device Manager show for "Network adapters"?

Hi Adam,

Apologies for the late reply. I have done a lot of testing with this issue as well. In the "Advanced" section of your Realtek, you can enable "Energy-Efficient Ethernet". When I enabled it, the connection became very stable (more than before, I would see drops quite quickly). In case it is not there in version 1156, I have installed version 1159 from the Realtek website.

Please try this and let me know the outcome. Thank you.

Forget the versions I mentioned, 11.59 was a different Realtek driver all the same and not used.