It seems when using isotope-posts with custom content types results in odd behavior.
I setup a shortcode, for my post type I want to display. No taxonomy, no filter, etc.
When the page loads, the initial posts are of the correct type, when endless scroll is activated, the plugin returns posts of a different content type. Use the Inspector and look at XHR requests, once the endless scroll is activated, the URL is for another cpt. I've posted the link below, if you'd like a login, email or pm me.
I am using the current git version of the plugin. The odd thing is that about three weeks ago, the plugin was working properly, so I'm at a little bit of a loss here...
hxxp://dev.studioxx.org/xx-evenements/