I am running XFce Desktop environment distributed by xubuntu but under ubuntu 20.04 (I have the choice when I start up between usual Ubuntu 20.04 ubuntu environment or the XFce Desktop that I installed for performance reasons). I have a Dell 630 Laptop with a Sierra LTE Module "MC7804". When I do a regular boot, the audio is choosing the default internal device "Built in Audio Analog Stereo" for both input and output devices. I use a Logitech headset. When I plug it in, it is also recognized automatically and the sound is redirected to it (whether it is connected after I booted or before). Because of https://bugzilla.xfce.org/show_bug.cgi?id=14782, I try to suspend often rather than lock the screen (nothing happens when I chose lock). After I wake the laptop up from suspend, the audio work on the headset for a few seconds, then when network comes up, it is redirected to a device called "MC7804" Analog stereo (for output) or mono (for input). It is systematic, whether or not I was using the headset before I suspended, it goes into this error. I would expect that after resume the same device is used as before going in suspend mode.
Is xfce4-session to blame for this? We have xfce4-pulseaudio-plugin which allows you to control the volume via a panel indicator, and that is all there is when it comes to Xfce and sound. I assume that the bug is in pulseaudio or the kernel.
Closing.