I made a vfr plan from 2 airports here in Brasil- SBYS and SBBQ.

I noted that the heading indicating in 'Heading M'(Plan Expander) doesn't matter with
the correct heading in FS2004, when I try to fly...

The error is arround 17 degrees.

I had to make fly all waypoints correcting the magnetic headings to plan...

There is a bug in south coordinates or I'm forgeting something ?

Thanks for help.