The problem was that there were dkms drivers that were tainting the -29 kernel.
You can see if you have a tainted kernel with:
grep -i taint /var/log/syslog*
Then I did a dkms remove of the broadcom and r8168 dkms drivers.
And I uninstalled:
- broadcom-sta-dkms
- r8168-dkms
rebooted, and the top panel icon/menu were back to normal.
Update #1:
Well, I spoke too soon. The problem is back. The ethernet interface is screwy. I booted into Windows 10, once, and the ethernet interface worked fine. I'll have to test some more, but it looks like a Ubuntu problem... one that only showed up after the -29 kernel update.
Update #2:
Lets try this again. I removed the GNOME shell extension GSConnect here, and then manually deleted the bits and pieces of software that it left behind, and then manually uninstalled kdeconnect. My network icon is back in the top panel, and the network menus now correctly show the ethernet and wireless interfaces... and funny enough, it also fixed a problem with Software & Updates where it wouldn't allow me to select/deselect repositories!
Update #3:
Well, everything in Update #2 didn't really fix the problem(s). I note that if I boot the machine with the wireless connected, and the ethernet unplugged, it all works fine. If I then connect the ethernet cable, it never connects, and it looks like I never obtain an IPv4 network address. I think that if I boot with the ethernet cable already connected, the original symptoms with the icon/menu are there. I don't believe that netplan has anyting to do with the problem. I also note, in case example of one, that if I boot Windows 10, then Ubuntu 18.04, it all seems to work as expected.
Update #4:
If you're running on a SSD, you run the risk of things booting faster than the network is coming online and then you'll need to modify the following file: /etc/systemd/system/network-online.target.wants/NetworkManager-wait-online.service
[Unit]
Description=Network Manager Wait Online
Documentation=man:nm-online(1)
Requires=NetworkManager.service
After=NetworkManager.service
Before=network-online.target
[Service]
Type=oneshot
ExecStart=/usr/bin/nm-online -s -q --timeout=60
RemainAfterExit=yes
[Install]
WantedBy=network-online.target
and change the timeout from 30
to 60
.
Update #5:
Darn. Update #4 really didn't fix the problem after all.
Update #6:
The network problems in 18.04 (and probably updated 16.xx too) occurred in kernels 4.15.0-29 through -36. Upgrading to 18.10 with its 4.18 kernel, fixes the problem! Yeah!