No more icons in context menu (LO6, Calc)

I have just installed Linux Mint 19 which comes with LO; I was using LO5 until now.

In Calc, the items in the context menus do not have an icon anymore: is this a bug on my system (theme-related or whatever), or a “feature” of version 6 or of the icon theme (I tried both Tango and Galaxy)?

It is a feature of Gnome apparently, See question 290489

I’m using LibreOffice under Ubuntu LTS 18.04 and I too have no icons under the context menus… It looks like this is a feature of LibreOffice 6.x.