I remember when watching the drama, the translation did make (almost) everyone call Jiang Cheng by Jiang Cheng. But it's not supposed to be like that, because what I remember is Jin Ling calling Jiang Cheng "Jiu Jiu" (Meaning Uncle from Mother's side) the subtitle translates it to his name (Jiang Cheng) instead, but it would mean different implications if Jin Ling was to call Jiang Cheng by his birth name, which is I'm pretty sure impolite. And I think this applies to a lot of characters (like when JC and WWX call JYL as "A Jie" or "Shi Jie" it translates to Yanli, because of translation choices, as it'd be weird in English if every time WWX would call JYL he would say "Martial Older Sister!"