We recently did a change to how trailing whitespace are handled, but this is probably something else if it’s the width of the space character in between words that is rendered differently.
I have solved this by setting the width of all 15 (fifteen!) different spaces of the font to the same value. It seems to me that the editor and the engine are using a different unicode (at least with my otf file exported with Glyphs).
I think I have found the problem. I had a similar issue with all the Cyrillic glyphs having extreme wide spaces. I modified the font but the glyphs was still wide in the game. So I did a Rebuild and the engine created again the font metric, while a simple Build did not, and the spaces are now correct.