tag is stripped ONLY on cron

hello,
i am facing a problem i could not track! i have made an autoposting plugin! it posts hourly! however, i put a button to emulate the cron function! that mean when I click the button, the same function that is executed on cron, is now executed! it is to manually verify the actions of cron function without waiting an hour!

the contents it post also has a script tag to create anchor so that spider can’t visit the links! it is something like:

<script type="text/javascript">
document.write('<a href="%MAIN_LINK%"><img src="IMG_URL" /></a>');
</script>

%MAIN_LINK% is replaced by cron function!

when I hit the button to manually execute the cron function, everything looks fine! that is the script tag is intact! and everything works without issue! however, when the actual cron runs by wordpress, the script tag is getting stripped! i don’t understand why same thing behaves differently!

any help?

thanks in advance!