I believe that I finally have an answer to this problem and understand that a solution will be publicly available soon..
First of all, my specific issue is that, with multiple Microsoft Surface devices (SB2 and SB3) running both Windows 11 and connected through multiple Microsoft Surface Docks (version 1 and 2), I would be disconnected from the wired network sporadically - sometimes as often as several times per-hour. When this happened, it seemed that the entire network interface was being 'surprise removed' (according to the Kernel-PnP event logs), and I would hear the Windows sound indicating that hardware had been disconnected, but all of my other devices connected to the dock would not be impacted (displays and USB devices). Most of the time it would reconnect right away, but the biggest problem that this caused for me was due to the reliance on a VPN connection for many of the applications that I use, so when the NIC would disappear, the VPN would go down, and my system would often become somewhat unresponsive for anywhere from a few seconds to a few minutes each time this happened, sometimes resulting in the need to forcefully reboot or power off.
The only workaround for me had been to disable/disconnect the wired NIC and only use the WiFi connection - until now..
I will also note that both of these machines functioned normally using either dock version when running Windows 10, so these issues were specific to Windows 11. I tried both OS upgrades and clean OS installations and both had the issue.
I have tried all of the things suggested in this post, as well as some others including some debugging which revealed that the NIC was, in fact, being removed - but no clear indication of why..
It seems that I finally brought this up with the right person who was familiar with the issue and pointed out that a commonality between these devices, as well as those from other vendors like Dell, is the fact that they are using Realtek network adapters and drivers, the latter of which apparently have this issue in some/many versions in Windows 11. I can't provide the version specifics, but I can tell you that after replacing the driver on my Realtek network adapter I have not been disconnected in a few days. I was advised that Realtek should be publishing a new version of the driver for my adapter soon which will address this issue, so hopefully this will resolve it for many of us. In the meantime, you might try using some older versions of the Realtek drivers to see if any are more stable than the latest that are currently available.
Best of luck to everyone! I can't be happier that mine has finally stabilized, so there is hope!