Hello,

I have tested with nvarchar2 in the query:
Quote
select N'Test message: j' from dual union
select N'Test message: k' from dual union
select N'Test message: ś' from dual union
select N'Test message: ź' from dual union
select N'Test message: ń' from dual;

The issue still persists.
I encountered the same issue with sqlplus, but, I encountered no issue with PL/SQL Developer nor with SQL Workbench/J.

[Linked Image]

I use system variable NLS_LANG="FRENCH_FRANCE.AL32UTF8"

Regards,
Stéphane.