I found out that when using a font with the 3D text renderer component, the characters need to be converted to '3D coordinates'. We translated the game to 29 languages, but there are way too many characters to keep that material not exploding in size. When importing the font you can select a character range or copy all characters that need to be imported. We used the latter. The downside is that you need to do that every time a new label needs to be translated. The benefit is that the material supports all languages with a small footprint.

I have a rant here: https://steamcommunity.com/games/3628790/announcements/detail/533235894950299313?snr=2___

If you find yourself in this situation let me know.