Before upgrading I could use sudo service network-manager restart when having connection issues. After upgrading to 21.10 the network-manager is still installed, but not as a service anymore. Restarting the "networking" service instead seems not to have the same effects (and didn't had before in 20.04).
How do I restart the network-manager in 21.10?
The NetworkManager service has been named NetworkManager for a while now, and network-manager service was kept around as a backwards-compatibility option (see What's the difference between network-manager.service and NetworkManager.service in Systemd?). It looks like that was finally dropped in Ubuntu 20.10 (Groovy Gorilla), and now only the NetworkManager name remains. You can use it like so:
sudo service NetworkManager start|stop|...
sudo systemctl start|stop|... NetworkManager
sudo systemctl start|stop|... NetworkManager.service
