Category: Installing LinuxCNC
To say Trixie is unreliable is untrue, particularly when it now an alpha release. The reason why Trixie was recommended is that it has a current version of Linuxcnc in its repos and you may have needed later drivers. The reason why I said to use XFCE or mate is that these are Xorg based desktops which Linuxcnc requires. Wayland desktops are problematic for Linuxcnc.
But when you see the messages about Realtek, this is because you do not have a useable HDD and the system is looking to boot off the network somewhere through the Realtek network interface. You don't wnt this.
The sad part about your issues is that it is due to you not having a suitable HDD/SSD installed on your system, My recommendation would be to go and buy a new SSD and install that in your PC as clearly something is wrong.