If you watch he big innings overseas, it has always been when the team in trouble and he has to get his eye in. If he batted like that every time overseas he would score more runs. That is mental/temperament thing not technical issue.
His issue is starting his innings overseas.
There is also a slight technique issue playing spin on turning tracks. His technique against spinners is tailored so much attacking spinners by using your feet to them. You can't always do that when the pitch is turning and he gets caught quite a fair bit.