F27 audio missing after login in Gnome
while the Audio sign (loudspeaker) is available at the login screen (next to the shutdown button) and audio is working (sound while moving the volume bar) the audio setting is missing after login in Gnome. In the audio settings all audio devices are gone.
The curious is that this already worked with a fresh upgraded F27 (from F26) and before i've done the first update with dnf.
edit funny, after the installation of ffmpeg, rtmpdump and vlc-extras via dnf i can play music and videos with rhythmbox and vlc or totem and with normal sound, but the volume bar in the gnome task bar still doesn't work. I have to regulate the volume directly at the software. But now the devices in the settings are here again :-)
With F27, the new audio stack pipewire was introduced. Perhaps this helps you track down the issue.