Oracle Reports only showing unreadable output

Oracle Reports is 12.2.1.3.0, Oracle Forms is 12.2.1.3.0, operating system both for database and weblogic is SunOS oas 5.11 11.4.43.113.3

setting LANG=de_DE.UTF-8 (on Oracle Reports Server host)

setting NLS_CHARACTERSET=WE8MSWIN1252 (in database)

setting NLS_NCHAR_CHARACTERSET=AL16UTF16 (in database)

all reports generated pdf files only show unreadable content like "ςερωαλτυνγ ϖον Ορδεν υνδ Αυσζειχηνυνγεν"

Which settings do i need in reports.sh or rwservlet.properties to fix this issue?

thank you very much for each advice

Regards Robert