@JuanGRodeja I tried the instructions on the page referenced by @advocatux (and the additional info here) but I could not make it work. Seems I was having the same problem as @juangrodeja: the Network Manager ignored the settings in my /etc/NetworkManager/system-connections/{SSID} file and created a new /etc/NetworkManager/system-connections/{SSID}-{UUID} file instead, without the "manual" config settings.

But I was able to successfully create a connection using the "nmtui" command-line tool over adb. My WiFi is working now!

This might be an easier option for users who don't feel comfortable editing the file by hand, but I think the TUI app requires the arrow keys for navigation so I'm not sure if it could be done from the phone's terminal.