When my computer is connected to ethernet, everything works fine. Without the cable, there are two problems: the booting is slow (it takes several minutes) and the computer does not automatically connect to wi-fi. The computer "thinks" it is connected to ethernet, as can be seen in the picture. I solve it by removing the "imaginary" ethernet connection but it is tiring to do each time I turn on the computer.

I tried to solve it myself and I had a theory that it has something to do with MAC addresses because of the last line of my NetworkManager.conf file (see below). I tried switching it to yes but it did not work.

[main]

plugins=ifupdown,keyfile



[ifupdown]

managed=true



[device]

wifi.scan-rand-mac-address=no

Additional files
/etc/network/interfaces

# interfaces(5) file used by ifup(8) and ifdown(8)

auto lo

iface lo inet loopback



auto enp3s0

iface enp3s0 inet dhcp

/etc/netplan/*.yaml (only one file 01-network-manager-all.yaml)

# Let NetworkManager manage all devices on this system

network:

  version: 2

  renderer: NetworkManager

Opening enp3s0:

Opening ifupdown:

Could you please give me a hint where the problem might be?