Disconnected wired connection on dock after startup - reason 'carrier-changed' after update to 18.10

[Lubomir Stanko]

I have a problem with wired connection while connected in docking station on startup after update from Ubuntu 18.04 to 18.10.

HW info:
Manufacturer: LENOVO
Product Name: 20HGS27000
Version: ThinkPad T470s
Serial Number: PC0MJA2W
BIOS Version: N1WET51W (Release Date: 09/14/2018)

System info:
$ lsb_release -rd
Description: Ubuntu 18.10
Release: 18.10
$ apt-cache policy network-manager
network-manager:
  Installed: 1.12.4-1ubuntu1
  Candidate: 1.12.4-1ubuntu1
  Version table:
 *** 1.12.4-1ubuntu1 500
        500 http://sk.archive.ubuntu.com/ubuntu cosmic/main amd64 Packages
        100 /var/lib/dpkg/status
$ uname -a
Linux citadel 4.18.0-10-generic #11-Ubuntu SMP Thu Oct 11 15:13:55 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

Steps to reproduce:
1. Update Ubuntu from 18.04 to 18.10
2. Start the laptop on docking station
3. Laptop is trying to connect automatically on wired connection after startup, but not successfully.
Log:
$ journalctl -u NetworkManager
nov 02 07:34:30 citadel NetworkManager[1158]: <info> [1541140470.6335] device (enp0s31f6): state change: ip-config -> unavailable (reason 'carrier-changed', sys-iface-state: 'managed')
nov 02 07:34:30 citadel NetworkManager[1158]: <info> [1541140470.6979] dhcp4 (enp0s31f6): canceled DHCP transaction, DHCP client pid 3447
nov 02 07:34:30 citadel NetworkManager[1158]: <info> [1541140470.6979] dhcp4 (enp0s31f6): state changed unknown -> done
nov 02 07:34:32 citadel NetworkManager[1158]: <info> [1541140472.3778] device (enp0s31f6): carrier: link connected
nov 02 07:34:32 citadel NetworkManager[1158]: <info> [1541140472.3780] device (enp0s31f6): state change: unavailable -> disconnected (reason 'carrier-changed', sys-iface-state: 'managed')
nov 02 07:34:32 citadel NetworkManager[1158]: <info> [1541140472.3787] policy: auto-activating connection 'Wired connection' (9a6bb9a9-2739-4bdc-b853-0eec29c6e42d)
nov 02 07:34:32 citadel NetworkManager[1158]: <info> [1541140472.3797] device (enp0s31f6): Activation: starting connection 'Wired connection' (9a6bb9a9-2739-4bdc-b853-0eec29c6e42d)
nov 02 07:34:32 citadel NetworkManager[1158]: <info> [1541140472.3799] device (enp0s31f6): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
nov 02 07:34:32 citadel NetworkManager[1158]: <info> [1541140472.4719] device (enp0s31f6): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
nov 02 07:34:32 citadel NetworkManager[1158]: <info> [1541140472.4725] device (enp0s31f6): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
nov 02 07:34:32 citadel NetworkManager[1158]: <info> [1541140472.4728] dhcp4 (enp0s31f6): activation: beginning transaction (timeout in 45 seconds)
nov 02 07:34:32 citadel NetworkManager[1158]: <info> [1541140472.4778] dhcp4 (enp0s31f6): dhclient started with pid 3689
nov 02 07:34:32 citadel dhclient[3689]: DHCPREQUEST of 10.10.20.214 on enp0s31f6 to 255.255.255.255 port 67 (xid=0x687f173)
nov 02 07:34:35 citadel dhclient[3689]: DHCPREQUEST of 10.10.20.214 on enp0s31f6 to 255.255.255.255 port 67 (xid=0x687f173)
nov 02 07:34:38 citadel NetworkManager[1158]: <info> [1541140478.4738] device (enp0s31f6): state change: ip-config -> unavailable (reason 'carrier-changed', sys-iface-state: 'managed')
nov 02 07:34:38 citadel NetworkManager[1158]: <info> [1541140478.5066] dhcp4 (enp0s31f6): canceled DHCP transaction, DHCP client pid 3689
nov 02 07:34:38 citadel NetworkManager[1158]: <info> [1541140478.5067] dhcp4 (enp0s31f6): state changed unknown -> done
nov 02 07:34:40 citadel NetworkManager[1158]: <info> [1541140480.2266] device (enp0s31f6): carrier: link connected
nov 02 07:34:40 citadel NetworkManager[1158]: <info> [1541140480.2273] device (enp0s31f6): state change: unavailable -> disconnected (reason 'carrier-changed', sys-iface-state: 'managed')
nov 02 07:34:40 citadel NetworkManager[1158]: <info> [1541140480.2298] policy: auto-activating connection 'Wired connection' (9a6bb9a9-2739-4bdc-b853-0eec29c6e42d)
nov 02 07:34:40 citadel NetworkManager[1158]: <info> [1541140480.2354] device (enp0s31f6): Activation: starting connection 'Wired connection' (9a6bb9a9-2739-4bdc-b853-0eec29c6e42d)
nov 02 07:34:40 citadel NetworkManager[1158]: <info> [1541140480.2361] device (enp0s31f6): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
nov 02 07:34:40 citadel NetworkManager[1158]: <info> [1541140480.3299] device (enp0s31f6): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
nov 02 07:34:40 citadel NetworkManager[1158]: <info> [1541140480.3315] device (enp0s31f6): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
nov 02 07:34:40 citadel NetworkManager[1158]: <info> [1541140480.3319] dhcp4 (enp0s31f6): activation: beginning transaction (timeout in 45 seconds)
nov 02 07:34:40 citadel NetworkManager[1158]: <info> [1541140480.3340] dhcp4 (enp0s31f6): dhclient started with pid 3739
nov 02 07:34:40 citadel dhclient[3739]: DHCPREQUEST of 10.10.20.214 on enp0s31f6 to 255.255.255.255 port 67 (xid=0x6ae6d0ef)

Workaround:
- Reconnect the wired connection manually or restart network manager - it is OK to do it for couple times but after each start it gets annoying

Previously installed working versions:
Ubuntu: 18.04
Linux kernel: 4.15.0-38-generic
Network Manager: 1.10.6-2ubuntu1

[Lubomir Stanko (stanko.lubomir)]

I've tried to clean install Ubuntu 18.10. I don't have this problem anymore. So I'm closing this issue. I suppose clean install could fix a lot of things.