
$ nmcli d 
DEVICE  TYPE      STATE         CONNECTION 
eth0    ethernet  connected     eth0       
BLA     team      disconnected  --         
wlan5   wifi      disconnected  --         
virbr0  bridge    unmanaged     --         
dummy0  dummy     unmanaged     --         
lo      loopback  unmanaged     --   

$ sudo ip link add name BBB type bridge

-----
NetworkManager[6094]: <info> (BBB): carrier is OFF
NetworkManager[6094]: <info> (BBB): new Bridge device (driver: 'bridge' ifindex: 3248)
NetworkManager[6094]: <info> (BBB): exported as /org/freedesktop/NetworkManager/Devices/9
NetworkManager[6094]: <info>     read connection 'BBB'
NetworkManager[6094]: <info> (BBB): device state change: unmanaged -> unavailable (reason 'connection-assumed') [10 20 41]
NetworkManager[6094]: <info> (BBB): device state change: unavailable -> disconnected (reason 'connection-assumed') [20 30 41]
NetworkManager[6094]: <info> Activation (BBB) starting connection 'BBB'
NetworkManager[6094]: <info> Activation (BBB) Stage 1 of 5 (Device Prepare) scheduled...
NetworkManager[6094]: <info> Activation (BBB) Stage 1 of 5 (Device Prepare) started...
NetworkManager[6094]: <info> (BBB): device state change: disconnected -> prepare (reason 'none') [30 40 0]
NetworkManager[6094]: <info> Activation (BBB) Stage 2 of 5 (Device Configure) scheduled...
NetworkManager[6094]: <info> Activation (BBB) Stage 1 of 5 (Device Prepare) complete.
NetworkManager[6094]: <info> Activation (BBB) Stage 2 of 5 (Device Configure) starting...
NetworkManager[6094]: <info> (BBB): device state change: prepare -> config (reason 'none') [40 50 0]
NetworkManager[6094]: <info> Activation (BBB) Stage 2 of 5 (Device Configure) successful.
NetworkManager[6094]: <info> Activation (BBB) Stage 2 of 5 (Device Configure) complete.
NetworkManager[6094]: <info> Activation (BBB) Stage 3 of 5 (IP Configure Start) scheduled.
NetworkManager[6094]: <info> Activation (BBB) Stage 3 of 5 (IP Configure Start) started...
NetworkManager[6094]: <info> (BBB): device state change: config -> ip-config (reason 'none') [50 70 0]
NetworkManager[6094]: <info> (BBB): IPv4 config waiting until carrier is on
NetworkManager[6094]: <info> (BBB): IPv6 config waiting until carrier is on
NetworkManager[6094]: <info> Activation (BBB) Stage 3 of 5 (IP Configure Start) complete.
-----

$ nmcli d
DEVICE  TYPE      STATE                                  CONNECTION 
eth0    ethernet  connected                              eth0       
BBB     bridge    connecting (getting IP configuration)  BBB        
BLA     team      disconnected                           --         
wlan5   wifi      disconnected                           --         
virbr0  bridge    unmanaged                              --         
dummy0  dummy     unmanaged                              --         
lo      loopback  unmanaged                              --  

$ nmcli c s -a
NAME  UUID                                  TYPE            DEVICE 
BBB   246f7db2-a2fd-4ef8-8d03-7fd154fef00c  bridge          BBB    
eth0  6e81314f-682e-42e8-94ed-5e2bc931d81b  802-3-ethernet  eth0  

$ dbus-send --system --print-reply --reply-timeout=120000 --type=method_call --dest='org.freedesktop.NetworkManager' '/org/freedesktop/NetworkManager' org.freedesktop.NetworkManager.GetDevices
method return sender=:1.1111 -> dest=:1.1129 reply_serial=2
   array [
      object path "/org/freedesktop/NetworkManager/Devices/0"
      object path "/org/freedesktop/NetworkManager/Devices/2"
      object path "/org/freedesktop/NetworkManager/Devices/4"
      object path "/org/freedesktop/NetworkManager/Devices/6"
      object path "/org/freedesktop/NetworkManager/Devices/7"
      object path "/org/freedesktop/NetworkManager/Devices/8"
      object path "/org/freedesktop/NetworkManager/Devices/9"
   ]

$ dbus-send --system --print-reply --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.DBus.Properties.Get string:org.freedesktop.NetworkManager string:ActiveConnections
method return sender=:1.1111 -> dest=:1.1130 reply_serial=2
   variant       array [
         object path "/org/freedesktop/NetworkManager/ActiveConnection/6"
         object path "/org/freedesktop/NetworkManager/ActiveConnection/0"
      ]

$ dbus-send --system --print-reply --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager/ActiveConnection/6 org.freedesktop.DBus.Properties.GetAll string:org.freedesktop.NetworkManager.Connection.Active
method return sender=:1.1111 -> dest=:1.1131 reply_serial=2
   array [
      dict entry(
         string "Connection"
         variant             object path "/org/freedesktop/NetworkManager/Settings/986"
      )
      dict entry(
         string "SpecificObject"
         variant             object path "/"
      )
      dict entry(
         string "Id"
         variant             string "BBB"
      )
      dict entry(
         string "Uuid"
         variant             string "246f7db2-a2fd-4ef8-8d03-7fd154fef00c"
      )
      dict entry(
         string "Type"
         variant             string "bridge"
      )
      dict entry(
         string "Devices"
         variant             array [
               object path "/org/freedesktop/NetworkManager/Devices/9"
            ]
      )
      dict entry(
         string "State"
         variant             uint32 1
      )
      dict entry(
         string "Default"
         variant             boolean false
      )
      dict entry(
         string "Ip4Config"
         variant             object path "/"
      )
      dict entry(
         string "Dhcp4Config"
         variant             object path "/"
      )
      dict entry(
         string "Default6"
         variant             boolean false
      )
      dict entry(
         string "Ip6Config"
         variant             object path "/"
      )
      dict entry(
         string "Dhcp6Config"
         variant             object path "/"
      )
      dict entry(
         string "Vpn"
         variant             boolean false
      )
      dict entry(
         string "Master"
         variant             object path "/"
      )
   ]


$ sudo ip link del BBB

$ nmcli d
DEVICE  TYPE      STATE         CONNECTION 
eth0    ethernet  connected     eth0       
BLA     team      disconnected  --         
wlan5   wifi      disconnected  --         
virbr0  bridge    unmanaged     --         
dummy0  dummy     unmanaged     --         
lo      loopback  unmanaged     --   

$ nmcli c s -a
NAME  UUID                                  TYPE            DEVICE 
BBB   246f7db2-a2fd-4ef8-8d03-7fd154fef00c  bridge          --     
eth0  6e81314f-682e-42e8-94ed-5e2bc931d81b  802-3-ethernet  eth0 

$ dbus-send --system --print-reply --reply-timeout=120000 --type=method_call --dest='org.freedesktop.NetworkManager' '/org/freedesktop/NetworkManager' org.freedesktop.NetworkManager.GetDevices
method return sender=:1.1111 -> dest=:1.1136 reply_serial=2
   array [
      object path "/org/freedesktop/NetworkManager/Devices/0"
      object path "/org/freedesktop/NetworkManager/Devices/2"
      object path "/org/freedesktop/NetworkManager/Devices/4"
      object path "/org/freedesktop/NetworkManager/Devices/6"
      object path "/org/freedesktop/NetworkManager/Devices/7"
      object path "/org/freedesktop/NetworkManager/Devices/8"
   ]

$ dbus-send --system --print-reply --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.DBus.Properties.Get string:org.freedesktop.NetworkManager string:ActiveConnections
method return sender=:1.1111 -> dest=:1.1135 reply_serial=2
   variant       array [
         object path "/org/freedesktop/NetworkManager/ActiveConnection/6"
         object path "/org/freedesktop/NetworkManager/ActiveConnection/0"
      ]



====================
after the fix 

$ sudo ip link del BBB

-----
NetworkManager[9363]: <info> (BBB): device state change: ip-config -> unmanaged (reason 'removed') [70 10 36]
NetworkManager[9363]: <info> (BBB): deactivating device (reason 'removed') [36]
-----

$ nmcli d
DEVICE  TYPE      STATE         CONNECTION 
eth0    ethernet  connected     eth0       
BLA     team      disconnected  --         
wlan5   wifi      disconnected  --         
virbr0  bridge    unmanaged     --         
dummy0  dummy     unmanaged     --         
lo      loopback  unmanaged     --  

$ nmcli c s -a
NAME  UUID                                  TYPE            DEVICE 
eth0  ba5b8161-e890-4531-9c7d-fac70865dd52  802-3-ethernet  eth0 

