Currently in 18.04 and 19.1 when you click on the network manager icon in the top panel you can choose a network connection but you can not edit one. To get to settings you have to click elsewhere. Since bluetooth is easily accessible from the top I click on it and advance to the network or wifi section of the settings menu. It would be helpful to be able to edit connections from the wifi icon.
suggest use the network applet available in menu - budgie applets.