Comment 5 for bug 1769386

I think I have the same issue on my nettop using "Pegatron RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller". It doesn't work out of the box on neither Ubuntu Server (bionic) nor Arch, but I used to run Ubuntu Server on this hardware around a year ago without any problems.

Someone else downgraded their kernel from 4.15 to 4.14 on Arch to solve this issue after updating, with identical hardware.

I'm linking some pastes that were requested in the IRC channel.
modinfo r8168 (I tried to fix things by installing r8168-dkms) > paste.ubuntu.com/p/2spYWX5t4k/
modinfo r8169 (I was asked to unload r8168 and load r1869) > https://paste.ubuntu.com/p/jg9rbKThWZ/
dhclient -v (it also takes 5 minutes to boot, until it times out) &> https://paste.ubuntu.com/p/D3JpycKrq3/