You should be using the r8125-dkms package from the AUR. I think it was using th r8169 kernel module but with the update to r8168 it failed to properly rebuild the kernel modules. I think if you install the r8125 you won’t have this issue. This is the 2.5 GBE Ethernet
That’s one solution, but not the easiest. r8168 blacklists r8169, and it doesn’t cover your network adapter anyway. So you can simply remove it (as you did). Then your network adapter would have worked with r8169. There’s no need to install the vendor driver r8125.
That’s what i was alluding to that it was probably working on the r8169 module. As far as being the easiest i don’t see any issue with installing r8125-dkms. It’s pretty easy and the OP shouldn’t have the issue any more. Yes he could have uninstalled the r8168 and see if it worked again.
But the op said!
“I downgraded the package from pacman cache, ran mkinitcpio -p linux but that didn’t solve anything.”
I can try uninstalling r8125-dkms to see if it still works.
The reason I went ahead is what @ricklinux said, quoting myself; I downgraded to a package that previously worked, so I didn’t think it would work by uninstalling it. Flawed reasoning perhaps on my behalf …
Either way, appreciate all the help and I’ll let you know if it works without r8125-dkms.
It is my understanding the rtl8125 was added to the r8169 module some time ago. So by all means check it out. There have been certain issues with Realtek chips where some work on the r8168 module and some work on the r8169. Some work on both like mine. That is the reason why the r8168 package was included at the time. It does cause issues though for users who don’t have the need for it.
It does load the kernel module which is r8169. The r8168 is an additional package that is added to EndeavourOS. So removing r8168 allows it to load the r8169 kernel module. When the r8168 package is installed it blacklists the r8169 kernel module so it won’t load. That is the reason your Ethernet quit working when you got an update and it updated the r8168 package.