After shutting down the Raspberry Pi 4 and rebooted the SSID is no longer broadcasted. I verified that the wlan0 interface is on with ifconfig.
How can I get the SSID to broadcast again?
It is hard to say what went wrong without logs from your device. If you can run the following command and share a picture of the output it would help
journalctl -xe
I reinstalled using the stable image you suggested elsewhere, so I am not sure what happened.