我正在使用带有 KDE Plasma 的 Trisquel 9（基于 Ubuntu 18.04 -- Bionic）。
我最近将自由 Linux 内核升级到 5.11.4-gnu，这需要重新启动许多系统服务。重新启动计算机后，我又可以正常使用有线互联网连接了。一段时间没有活动后，系统自动挂起。当我尝试再次使用互联网时，却无法正常工作。
网络管理器小程序是红色的。它列出了活动连接。虽然我已连接并且已插入以太网电缆，但我无法访问互联网。
在看到网上各种关于无法连接有线网络的帖子后，我将计算机重新启动到较旧的内核版本 (5.9.2-gnu)，看看是否能解决问题，但同样没有解决。
以下是在 Konsole 中发出以下命令的结果：
$ sudo lshw -C network
*-network
description: Ethernet interface
product: Ethernet Connection I219-LM
vendor: Intel Corporation
physical id: 1f.6
bus info: pci@0000:00:1f.6
logical name: enp0s31f6
version: 21
serial: ec:21:e5:0f:3e:1f
capacity: 1Gbit/s
width: 32 bits
clock: 33MHz
capabilities: pm msi cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=5.9.2-gnu firmware=0.13-
以下是在 Konsole 中发出以下命令的结果：
$ systemctl status NetworkManager.service
● NetworkManager.service - Network Manager
Loaded: loaded (/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled)
Active: active (running) since Wed 2021-03-17 10:59:03 CDT; 14min ago
Docs: man:NetworkManager(8)
Main PID: 5359 (NetworkManager)
Tasks: 3 (limit: 4915)
CGroup: /system.slice/NetworkManager.service
└─5359 /usr/sbin/NetworkManager --no-daemon
Mar 17 11:04:09 nvsu NetworkManager[5359]: <info> [1615997049.4374] keyfile: add connection in-memory (c23e1caa-65dd-494c-8ca8-8a88dc74127c,"enp0s31f6")
Mar 17 11:04:09 nvsu NetworkManager[5359]: <info> [1615997049.4404] device (enp0s31f6): state change: unavailable -> disconnected (reason 'connection-assumed', sys-iface-state: 'external')
Mar 17 11:04:09 nvsu NetworkManager[5359]: <info> [1615997049.4450] device (enp0s31f6): Activation: starting connection 'enp0s31f6' (c23e1caa-65dd-494c-8ca8-8a88dc74127c)
Mar 17 11:04:09 nvsu NetworkManager[5359]: <info> [1615997049.4744] device (enp0s31f6): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'external')
Mar 17 11:04:09 nvsu NetworkManager[5359]: <info> [1615997049.4750] device (enp0s31f6): state change: prepare -> config (reason 'none', sys-iface-state: 'external')
Mar 17 11:04:09 nvsu NetworkManager[5359]: <info> [1615997049.4753] device (enp0s31f6): state change: config -> ip-config (reason 'none', sys-iface-state: 'external')
Mar 17 11:04:09 nvsu NetworkManager[5359]: <info> [1615997049.4754] device (enp0s31f6): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'external')
Mar 17 11:04:09 nvsu NetworkManager[5359]: <info> [1615997049.4757] device (enp0s31f6): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'external')
Mar 17 11:04:09 nvsu NetworkManager[5359]: <info> [1615997049.4759] device (enp0s31f6): state change: secondaries -> activated (reason 'none', sys-iface-state: 'external')
Mar 17 11:04:09 nvsu NetworkManager[5359]: <info> [1615997049.4788] device (enp0s31f6): Activation: successful, device activated.
我应该怎么做才能让我的有线互联网连接重新正常工作？
谢谢。