Icon mode Gtk-Critical messages

When appfinder is set to "View items as icons", in non-collapsed mode, and starting to search/filter for an app, every filter event emits a

(xfce4-appfinder:258632): Gtk-CRITICAL **: 17:54:55.395: gtk_tree_model_sort_real_unref_node: assertion 'elt->ref_count > 0' failed

Regardless of the message, filtering still works. When not in icon mode, there is no such error displayed.

xfce4-appfinder 4.18.0git-c04300f (Xfce 4.18)