When sorting on a translated field, the results are being sorted based on the English text, not the translation.
Pre-requisite: Instance should have any I18N Language installed (ex: French | com.snc.i18n.french)
Expected: Column should be sorted in French
Actual: Column is still sorted by English (Key) value
Sorting is designed to be done by the key for those fields. Since working by design, no plan to address this in one of the foreseeable upcoming releases.
You can submit your exact business case for this request in our newly updated Idea Portal, which replaces the old Enhancement Request process. Please see KB0755878 for more information on this process: https://hi.service-now.com/kb_view.do?sys_kb_id=abf3ef9ddbac4cd423f4a345ca961963