CSV importer doesn't import "Select List (cascading)" field data correctly.

Issue Summary

CSV importer doesn't import Select List (cascading) field data correctly.
This problem happens only when we use Issues > Import Issues from CSV on the top page.
This problem never happens when we import CSV using System > External System Import in the Administration page.

Steps to Reproduce

1. Create a project
2. Add Select List (cascading) custom field and set their options
3. Associate the custom field to the project you created on step1
4. Import CSV from Issues > Import Issues from CSV

Expected Results

The CSV data should be imported to JIRA correctly.

Actual Results

Select List (cascading) custom field data (especially the child option) was not imported.
See the screenshot attached: Select List (cascading) CSV import failed.png

Workaround

Use System > External System Import in Administration page instead.