My laptop suspends automatically after ten minutes. Recently, on resume, the network (via ethernet) appears to be up according to the tray icon, but I cannot connect to the internet. I recently upgraded from Plasma 5.3.2 to 5.4.0, and never saw this problem in the past.

Previously, on resume, I would see a double notification. The first would tell me that I had disconnected from the network, and the second would tell me I reconnected. I'm unsure if it's relevant, but I don't see this now. I do currently see the tray icon go briefly red, then back to black. I cannot connect to the network whether suspending automatically or manually.

I attempted to restart Network Manager with `sudo systemctl restart NetworkManager`, and Plasma with `kbuildsycoca5; kquitapp5 plasmashell; plasmashell`, but neither helped. I also attempted to pull the ethernet cord out and replace it, but this also failed. The only thing that worked was a full system restart.

Is there a way to automatically or manually reconnect to the network?

EDIT
I'm using Arch Linux. I looked at `sudo journalctl`, but there was nothing obvious in there. However, I'm not 100% what to look for.

EDIT2
This only occurs with the ethernet connection. The Wifi connection reconnects perfectly.

EDIT3
My "default" ethernet connection works fine. I'm only having trouble with my work ethernet connection, where I have to manually specify an IP address (and netmask, gateway and DNA servers).

EDIT4
I just realised that NetworkManager was recently upgraded. I've filed a bug. If you have a viable workaround in the meantime, please let me know!