Unfortunately, I'm unable to test this (and I'm not familiar with how computers handle RTL languages) because apparently my game doesn't use a font that supports Hebrew so I don't see anything in-game. My first guess would be that maybe the game can't handle RTL and LTR languages being mixed in a single line (I'm not even entirely sure it handles RTL at all but I assume it does). What happens if the only text being printed is RTL (Hebrew), with and without the data provided by the JSON (I doubt it has anything to do with the JSON file itself).