KDENLIVE is not showing up fully localized

WHen I launch Kdenlive on Leap 15 with Xfce I’m seeing part of the menus in Polish and part in English. Any Ideas why?
Also on start Kdenlive compained about missing breeze icons and freier plugins - which I fixed by installing manually (by I guess those should have been pulled by package management system).
In general I have to admit I’m having more packaging related issues with Leap 15 than I had with 42.3 (where I’ve encountered almost none).