Not all results showing up

Hello

I have a weird issue, not all posts that match the results show up in the search results. For example when doing a search for “discussion” ( http://www.cogdesign.com/?s=discussion ) for example the following entry ( http://www.cogdesign.com/journal/disscusion-day/ ) doesn’t show up in the results.

What could cause such an issue? I rebuilt the index multiple times but still no luck.

Regards,
Zoltan

https://wordpress.org/plugins/relevanssi/