For the last couple of years, it has taken a long time (sometimes as long as 30 seconds!) for the list of available WiFi networks to be displayed after clicking the icon at the top of the screen.
I have over 400 "preferred" (saved) networks. Does that have something to do with it? I like to keep them because I travel a lot and it's nice to come back to a place and have my system automatically log in without any effort on my part.
I have written a command line application to manage WiFi independently of the GUI (at https://github.com/keithrbennett/wifiwand), but would prefer to have both options available to me.