Comment 7 for bug 1862767

The output of the command you asked for is

$ systemctl status NetworkManager
● NetworkManager.service - Network Manager
   Loaded: loaded (/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2020-02-17 08:51:10 -03; 5h 33min ago
     Docs: man:NetworkManager(8)
 Main PID: 1206 (NetworkManager)
    Tasks: 3 (limit: 4915)
   Memory: 22.7M
   CGroup: /system.slice/NetworkManager.service
           └─1206 /usr/sbin/NetworkManager --no-daemon

fev 17 08:51:53 adcamp NetworkManager[1206]: <info> [1581940313.9009] device (p2p-dev-wlp3s0): supplicant management interface state: com
fev 17 08:51:53 adcamp NetworkManager[1206]: <info> [1581940313.9421] device (wlp3s0): supplicant interface state: authenticating -> asso
fev 17 08:51:53 adcamp NetworkManager[1206]: <info> [1581940313.9422] device (p2p-dev-wlp3s0): supplicant management interface state: aut
fev 17 08:51:53 adcamp NetworkManager[1206]: <info> [1581940313.9453] device (wlp3s0): supplicant interface state: associating -> associa
fev 17 08:51:53 adcamp NetworkManager[1206]: <info> [1581940313.9453] device (p2p-dev-wlp3s0): supplicant management interface state: ass
fev 17 08:51:54 adcamp NetworkManager[1206]: <info> [1581940314.0257] device (wlp3s0): supplicant interface state: associated -> complete
fev 17 08:51:54 adcamp NetworkManager[1206]: <info> [1581940314.0274] device (p2p-dev-wlp3s0): supplicant management interface state: ass
fev 17 08:55:57 adcamp NetworkManager[1206]: <info> [1581940557.0456] agent-manager: req[0x5652c8d3ab10, :1.407/org.gnome.Shell.NetworkAg
fev 17 09:00:01 adcamp NetworkManager[1206]: <info> [1581940801.3983] dhcp4 (wlp3s0): state changed bound -> expire
fev 17 09:00:01 adcamp NetworkManager[1206]: <info> [1581940801.3985] device (wlp3s0): DHCPv4: 480 seconds grace period started

As the other thread mentions, it seems that it has to do with the NetworkManager. Since mine was already running (as I understood from the output above), I restarted it with

$systemctl restart NetworkManager

and the settings are working again. But the outputs of the status seems the same to me. See, after restart

$ systemctl status NetworkManager
● NetworkManager.service - Network Manager
   Loaded: loaded (/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2020-02-17 15:15:22 -03; 14s ago
     Docs: man:NetworkManager(8)
 Main PID: 9778 (NetworkManager)
    Tasks: 4 (limit: 4915)
   Memory: 7.7M
   CGroup: /system.slice/NetworkManager.service
           └─9778 /usr/sbin/NetworkManager --no-daemon

fev 17 15:15:29 adcamp NetworkManager[9778]: <info> [1581963329.8784] device (p2p-dev-wlp3s0): supplicant management interface state: dis
fev 17 15:15:29 adcamp NetworkManager[9778]: <info> [1581963329.8802] device (wlp3s0): supplicant interface state: authenticating -> asso
fev 17 15:15:29 adcamp NetworkManager[9778]: <info> [1581963329.8802] device (p2p-dev-wlp3s0): supplicant management interface state: aut
fev 17 15:15:29 adcamp NetworkManager[9778]: <info> [1581963329.8924] device (wlp3s0): supplicant interface state: associating -> associa
fev 17 15:15:29 adcamp NetworkManager[9778]: <info> [1581963329.8924] device (p2p-dev-wlp3s0): supplicant management interface state: ass
fev 17 15:15:30 adcamp NetworkManager[9778]: <info> [1581963330.0012] device (wlp3s0): supplicant interface state: associated -> complete
fev 17 15:15:30 adcamp NetworkManager[9778]: <info> [1581963330.0013] device (wlp3s0): Activation: (wifi) Stage 2 of 5 (Device Configure)
fev 17 15:15:30 adcamp NetworkManager[9778]: <info> [1581963330.0013] device (p2p-dev-wlp3s0): supplicant management interface state: ass
fev 17 15:15:30 adcamp NetworkManager[9778]: <info> [1581963330.0015] device (wlp3s0): state change: config -> ip-config (reason 'none',
fev 17 15:15:30 adcamp NetworkManager[9778]: <info> [1581963330.0020] dhcp4 (wlp3s0): activation: beginning transaction (timeout in 45 se

However, the settings open only once. After closing it, it gives the same error. And if I restart the NetworkManager it opens again (once).