xubuntu ethernet does not reconnect unless computer restarted, after power off/on modem or manually off/on "enable networking"

[H]

Xubuntu 19.04, 64bit, encrypted drive, using a desktop computer with ethernet to connect. Connects fine. Use openvpn also (from terminal). When the modem is turned off and on, or when the modem remains on but the ethernet connection is disabled (by unticking) and then ticking again "enable networking" in the applet taskbar, the connection does not re-establish. This is irregardless of the vpn, which even if i turn off, will not affect the lack of reconnection.

If i ping bing.com, after trying to reconnect, I get back one response, but no multiple responses.

ping bing.com
PING bing.com (204.79.197.200) 56(84) bytes of data.

This is slightly different to no connection being present, as then I would not even get back a single ping:

"ping: bing.com: Temporary failure in name resolution"

The only way to get a connection back is by restarting the system. And then it works fine.

This is not an issue for ubuntu mate 19.04. The reconnection works fine, with no restart required.

[Sebastien Bacher (seb128)]

Thank you for your bug report, could you add your journalctl -b 0 log after getting the issue?

[H (h2x4t)]

- Logs begin at Wed 2019-07-10 19:00:46 BST, end at Sat 2019-07-13 05:18:08 BST. --
Jul 13 05:07:50 mbox kernel: Linux version 4.18.0-25-generic (buildd@lgw01-amd64-033) (gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)) #26~18.04.1-Ubuntu SMP Thu Jun 27 07:28:31 UTC 2019 (U
Jul 13 05:07:50 mbox kernel: Command line: BOOT_IMAGE=/vmlinuz-4.18.0-25-generic root=/dev/mapper/xubuntu--vg-root ro quiet splash vt.handoff=1
Jul 13 05:07:50 mbox kernel: KERNEL supported cpus:
Jul 13 05:07:50 mbox kernel: Intel GenuineIntel
Jul 13 05:07:50 mbox kernel: AMD AuthenticAMD
Jul 13 05:07:50 mbox kernel: Centaur CentaurHauls
Jul 13 05:07:50 mbox kernel: x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers'
Jul 13 05:07:50 mbox kernel: x86/fpu: Supporting XSAVE feature 0x002: 'SSE registers'
Jul 13 05:07:50 mbox kernel: x86/fpu: Supporting XSAVE feature 0x004: 'AVX registers'
Jul 13 05:07:50 mbox kernel: x86/fpu: xstate_offset[2]: 576, xstate_sizes[2]: 256
Jul 13 05:07:50 mbox kernel: x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'standard' format.
Jul 13 05:07:50 mbox kernel: BIOS-provided physical RAM map:
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x0000000000000000-0x000000000009d7ff] usable
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x000000000009d800-0x000000000009ffff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x0000000000100000-0x000000001fffffff] usable
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x0000000020000000-0x00000000201fffff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x0000000020200000-0x0000000040003fff] usable
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x0000000040004000-0x0000000040004fff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x0000000040005000-0x000000009bfa6fff] usable
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x000000009bfa7000-0x000000009c2cbfff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x000000009c2cc000-0x000000009c2dbfff] ACPI data
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x000000009c2dc000-0x000000009c3f1fff] ACPI NVS
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x000000009c3f2000-0x000000009c68efff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x000000009c68f000-0x000000009c68ffff] usable
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x000000009c690000-0x000000009c6d2fff] ACPI NVS
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x000000009c6d3000-0x000000009cffffff] usable
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x000000009d000000-0x000000009f9fffff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x00000000f8000000-0x00000000fbffffff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x00000000fed00000-0x00000000fed03fff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x00000000fed1c000-0x00000000fed1ffff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved
Jul 13 05:07:50 mbox kernel: BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved
Jul 1...

[Launchpad Janitor (janitor)]

[Expired for network-manager (Ubuntu) because there has been no activity for 60 days.]