I already did a research on facebook as well in here, the solution I landed is on this page
Facebook Iframe App with multiple pages in Safari Session Variables not persisting
also I already did include this code but still not working
<?php header('P3P:CP="IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT"');
but its still not working, is Facebook implemented a new technique for cross-domain cookies/sessions for iframe in Safari?
I hope you can help me due to I'm already search any solution for 2 days and I cant successfully fix this issue.
thank you.