Icons missing in pavucontrol

The “lock channels” and “set as fallback” icons are missing for me in pavucontrol in 13.1 (see screen-shot).


I did a quick search, and I see that this was a problem in Ubuntu back in 2009 (see https://bugs.launchpad.net/ubuntu/+source/oxygen-icons/+bug/486605) but only for the Oxygen theme. I’ve tried other icon themes - even the Default Gnome Theme - and the icons are still missing.

Is anyone else having this problem?

I guess this is this bug:

An update to fix it should be released soon…