My Beocreate system with a RPi 3B+ and HifiberryOS has suddenly stopped connecting over WiFi. If I connect an ethernet cable or attach a monitor, I can see on the network page in the GUI that the RPi can see the available networks, including mine, which are listed as 'Saved'. But the Wifi IP address is listed as 'No address'.
I have of course tried rebooting. I have tried disabling/enabling Wifi, and reentering the password for my router. I also tried deleting my network, and recreating it. The network just seems to be added to the list, with no attempt to connect. Finally I tried updating to the latest HifiberryOS version. None of these actions made any difference. I don't see any error messages in dmesg.
Any suggestions on how to get my Wifi working again? How do I get it to switch to another SSID? I have 3 different ones to choose from, but it won't connect to any of them any more.