Dear Mastan,
As your BASIS team to check SPAD configuration in the plants where it is working and where it is not working.
Also convert the spool to PDF and using program RSTXPDFT4 in SE38 and try printing that PDF outside SAP on the printer which is converting the symbol -> If this prints fine, then issue is with SPAD settings only.
In SPAD it is possible to find if any settings have been changed/modified recently.
Best Regards,
Ameya B.