How do I gather information to file this specific bug report?

I am on Kubuntu 21.04. I have a 3080 ti and nvidia-driver-470 installed through apt.

Everything works except when I try to click on the volume tray applet, or launch pavucontrol-qt directly, the entire display server crashes and I'm stuck at a black screen until I switch to a different tty and do sudo systemctl restart sddm

I'm not sure which package the bug belongs to, nvidia, xorg, or pavucontrol. Nor do I know how to gather information for this. https://help.ubuntu.com/community/ReportingBugs tells me to modify a gdm3 config file. Except I'm on Kubuntu and use sddm, not gdm.