I have a Lenovo Z510 with the Realtek RTL810xE PCI Express ethernet chip. It requires the r8169 driver. Endeavour OS installs Realtek r8168 and that installation blacklists r8169.
https://git.archlinux.org/svntogit/community.git/tree/trunk/PKGBUILD?h=packages/r8168#n40
If your system ethernet card needs r8169 you can:
Keep editing /usr/lib/modeprob.d/r8168.conf to comment out the blacklisting of r8169. It gets added with every update of the r8168 driver.
Or:
Uninstall r8168 and that will remove the blacklisting.
sudo pacman -Rsn r8168
and then reboot.
Also see: Why is r8169 blacklisted?
Every time I reinstall EndeavourOS I do the online install via WiFi and then uninstall r8168 on first boot.