Ethernet connection not working on a fresh install

The weirdest problem I’ve ever encountered :

I have two installed systems on two different hard drives.

One hard drive with Windows 10, and another one with Manjaro 20.

I also have an USB key with a live system of Manjaro 20.

Whatever is the last system I booted from, I have no Ethernet connection on Manajaro 20.

Whatever is the last system I booted from, I have an Ethernet connection on Windows 10.

If the last system I booted from was Windows, I have an Ethernet connection on the live USB Key.

If the last system I booted from was Manjaro 20, I have no Ethernet connection on the live USB Key.

DHCPCD gives me this :

eno1: soliciting an IPv6 router

eno1: soliciting a DHCP lease

eno1: no IPv6 routers available

timed out

Please help, thanks in advance ^w^

This is probably not the same problem, but … about a year ago a fresh install of Manjaro Plasma broke my ethernet. An upgrade to the latest stable kernel and a reboot solved the problem.

In your Windows, disable fast startup. That is known to mess with the hardware state when rebooting to other system…