Hi, The guys at [1] confirm the problem goes away after [2] and don't mention the disappearance of the shadows. However, in case they missed it somehow, I'd suggest setting textstyle to 1 instead of 0. It might work.
[1] https://github.com/numixproject/numix-gtk-theme/issues/492 [2] https://github.com/numixproject/numix-gtk-theme/pull/496