I usually use a usb modem. In systemd, after enabling and starting the Network Manager service, and after closing systemd manager and reopening it, the service is not started. The “connman” and “NetworkManager” services are also enabled and running. After reboot the situation unchanged. The Network Management applet does not appear in the task bar.
So far everything has been OK, but after some time, after waking up from hibernation or sleep or hybrid-mode, problems with network connectivity have begun. I can not connect to the internet at all. In addition, it happened that cinnamon has crashed earlier. Can any of the services conflict?