Plank is not using system icon set anymore

After xfce4 got updated to version 4.16 plank stopped using system icon set I have chosen. I have tried different icon themes and gtk-themes, but it has no effect. Is it only me or is this a bug? My current icon theme is Mcmojave-circle-blue-dark, but as you can see in the screenshot it’s not show in plank…

Plank is not part of the recent upgrades, so this sounds weird to me. I use plank (on XFCE) and it is normal here (and several other places!). I would start my investigation by looking at the contents of the .desktop files in /usr/share/applications - they have an Icon= line in them…

Well, if I go to /usr/share/applications for example Thunar it looks like this:

Exec=thunar %F

I changed the path to icon theme I’m using at the moment and it worked. Now I got rid of that damn hammer icon. But it’s not very handy way to manage icons in plank. I have never had to do it that way. Plank has always used the current system icons before.