Character problem on aggregation for 5.4.0

When searching non-aggregation query, I see characters as " I\u015F\u0131k" in a non-analyzed field. but when I search with aggregation ElastichSearch puts question mark like " I??k" , I couldn't find any way of getting that word like" I\u015F\u0131k" or its original form like "ışık" in aggregation query.
What do you think about reason of this case ?
(solved.. it 's just proxy problem , not about ElastichSearch)