Random freeze when clicking on xfce4-pulseaudio-plugin

Hello, I possibly found a bug while using :

OS: Gentoo Linux, AMD64, hardened profile, version 23.0
Xfce4: 4.18-r1
Pulse audio plugin: 0.4.8
Xfwm: 4.18.0
Using X, I don't think Xfce4 supports Wayland, anyway

Description of the problem: Since yesterday, once in a while (2 times yesterday, once this morning) when I click on the icon in the xfce4-panel for the Pulse Audio plugins to, for example, change my audio output, the system notification shows the volume level going very fast to 0 in a few seconds, even if I try to increase it and after a few seconds almost the whole desktop freeze.

What's working: Moving the mouse, hearing sound from the application (e.g firefox).

What's not working: Everything else, the keyboard only respond if I call the shortcuts for TTY at this point. I can't either call alt+f2 and run the command from here, my only hope at this moment is the TTY. When I click on an application button in my list of application in the panel, it shows that it got the click (changing the visual slightly for the icon) but nothing happen then.

How I work around this: It comes back to a working DE if I use systemd to restart lightdm.

Something I need to try: Someone has suggested to me on #xfce@libera.chat to instead kill the xfwm process and then start it back and see. I did not had the occasion for now to test that. Will do and report here once I got a result from that.

I don't know what else I could bring to help you know if it's a bug, a problem from my setup or from Gentoo. Before asking the Gentoo team I think I have to come here first.

I did not find in the bug list of Xfce something looking like my problem. Also not on the gentoo bug trackers for the 3 probably concerned packages (xfce4-meta, xfce4-pulseaudio-plugin and xfwm4).

If you need more, please, ask.

Regards, GASPARD DE RENEFORT Kévin