csv file upload epic issue is not displaying on roadmap

[taehunchoi]

i uploaded csv file which is written in Korean.

1. import is successful

2. i can see all issue list from backlog or issues tab

3. roadmap tab is not showing any epic issues

--- work around ---

4. i updated all epic issue name by self copying its text and paste it again.

5. now i can see the epic issues from roadmap

here is the sample

Component,Issue Type,Epic Name,Epic Link,Summary,Assignee,Priority,issue id,parent id,Point
Hub,epic,서비스 가입 및 로그인,,서비스 가입 및 로그인,taehunchoi@zinnotech.com,3,1,,
Hub,story,,서비스 가입 및 로그인,사용자는 이메일 주소를 이용하여 시스템에 가입할 수 있다,taehunchoi@zinnotech.com,3,2,,3
Hub,sub-task,,,e-mail 주소 validation,taehunchoi@zinnotech.com,3,,2,1
Hub,sub-task,,,비밀번호 암호화,taehunchoi@zinnotech.com,3,,2,1
Hub,story,,서비스 가입 및 로그인,사용자는 등록된 이메일 인증이 완료되어야 시스템 사용이 가능하다,taehunchoi@zinnotech.com,3,3,,2