Ubuntu Server通过安装盘配置WiFi后无法使用Network Manager的问题求助

最近我用Live ISO装了Ubuntu Server，安装的时候特意配置了WiFi网络，结果现在系统装好后，Network Manager完全没法用——不管是用nmcli还是nmtui，都看不到任何WiFi连接列表，我的WiFi接口还显示成“不可用”状态。但奇怪的是WiFi本身是好的，我用sudo iwlist wlp108s0 scanning命令能正常扫描到周围的WiFi网络。有没有大佬能给点排查思路？

下面是我用网络调试脚本导出的相关信息片段：

网络管理器状态 #

已安装的管理器： #

• NetworkManager

运行进程： #

root        1129       1  0 22:09 ?        00:00:00 /usr/sbin/NetworkManager --no-daemon

NetworkManager WiFi设备详情（wlp108s0） #

GENERAL.DEVICE:                         wlp108s0
GENERAL.TYPE:                           wifi
GENERAL.NM-TYPE:                        NMDeviceWifi
GENERAL.DBUS-PATH:                      /org/freedesktop/NetworkManager/Devices/2
GENERAL.VENDOR:                         Intel Corporation
GENERAL.PRODUCT:                        Wireless 8265 / 8275
GENERAL.DRIVER:                         iwlwifi
GENERAL.DRIVER-VERSION:                 5.15.0-92-generic
GENERAL.FIRMWARE-VERSION:               36.ca7b901d.0 8265-36.ucode
GENERAL.HWADDR:                         <MAC 'wlp108s0' [IF1]>
GENERAL.MTU:                            1500
GENERAL.STATE:                          20 (unavailable)
GENERAL.REASON:                         41 (The device's existing connection was assumed)
GENERAL.IP4-CONNECTIVITY:               1 (none)
GENERAL.IP6-CONNECTIVITY:               1 (none)
GENERAL.UDI:                            /sys/devices/pci0000:00/0000:00:1c.4/0000:6c:00.0/net/wlp108s0
GENERAL.PATH:                           pci-0000:6c:00.0
GENERAL.IP-IFACE:                       --
GENERAL.IS-SOFTWARE:                    no
GENERAL.NM-MANAGED:                     yes
GENERAL.AUTOCONNECT:                    yes
GENERAL.FIRMWARE-MISSING:               no
GENERAL.NM-PLUGIN-MISSING:              no
GENERAL.PHYS-PORT-ID:                   --
GENERAL.CONNECTION:                     --
GENERAL.CON-UUID:                       --
GENERAL.CON-PATH:                       --
GENERAL.METERED:                        unknown
CAPABILITIES.CARRIER-DETECT:            no
CAPABILITIES.SPEED:                     unknown
CAPABILITIES.IS-SOFTWARE:               no
CAPABILITIES.SRIOV:                     no
INTERFACE-FLAGS.UP:                     yes
INTERFACE-FLAGS.LOWER-UP:               yes
INTERFACE-FLAGS.CARRIER:                yes
INTERFACE-FLAGS.PROMISC:                no
WIFI-PROPERTIES.WEP:                    yes
WIFI-PROPERTIES.WPA:                    yes
WIFI-PROPERTIES.WPA2:                   yes
WIFI-PROPERTIES.TKIP:                   yes
WIFI-PROPERTIES.CCMP:                   yes
WIFI-PROPERTIES.AP:                     yes
WIFI-PROPERTIES.ADHOC:                  yes
WIFI-PROPERTIES.2GHZ:                   yes
WIFI-PROPERTIES.5GHZ:                   yes
WIFI-PROPERTIES.MESH:                   no
WIFI-PROPERTIES.IBSS-RSN:               yes
IP4.ADDRESS[1]:                         192.168.1.14/24
IP4.GATEWAY:                            192.168.1.1
IP4.ROUTE[1]:                           dst = 192.168.1.0/24, nh = 0.0.0.0, mt = 600
IP4.ROUTE[2]:                           dst = 192.168.1.1/32, nh = 0.0.0.0, mt = 600
IP4.ROUTE[3]:                           dst = 0.0.0.0/0, nh = 192.168.1.1, mt = 600
IP6.ADDRESS[1]:                         fe80::<IP6 'wlp108s0' [IF1]>/64
IP6.GATEWAY:                            --
IP6.ROUTE[1]:                           dst = fe80::/64, nh = ::, mt = 256
CONNECTIONS.AVAILABLE-CONNECTION-PATHS: --
SSID  BSSID  MODE  CHAN  FREQ  RATE  SIGNAL  BARS  SECURITY  ACTIVE  IN-USE

NetworkManager.state 文件内容 #

[main]
NetworkingEnabled=true
WirelessEnabled=true
WWANEnabled=true

NetworkManager 配置文件汇总 #

/etc/NetworkManager/conf.d/default-wifi-powersave-on.conf #

[connection]
wifi.powersave = 3

/etc/NetworkManager/NetworkManager.conf #

[main]
plugins=ifupdown,keyfile
[ifupdown]
managed=false
[device]
wifi.scan-rand-mac-address=no

/usr/lib/NetworkManager/conf.d/10-dns-resolved.conf #

[main]
dns=systemd-resolved

/usr/lib/NetworkManager/conf.d/10-globally-managed-devices.conf #

[keyfile]
unmanaged-devices=*,except:type:wifi,except:type:gsm,except:type:cdma

/usr/lib/NetworkManager/conf.d/no-mac-addr-change.conf #

[device-31-mac-addr-change]
match-device=driver:eagle_sdio,driver:wl
wifi.scan-rand-mac-address=no

NetworkManager 配置文件（为空） #

备注：内容来源于stack exchange，提问作者ADRIANO782