Comment 5 for bug 1948677

thanks to pavucontrol, now i can get sound to my external speakers across reboots

In the sound section in the gnome settings panel, the dropdown list displays 2 outputs:
Headphones
Line out

the output device was set to Headphones because it was the setting in 21.04 and it worked.

Unfortunately, it's not possible to mute/umute something from this panel

I installed pavucontrol to unmute the Line out and set as the default output.

hope this help
you can close this bug