Portfolio Shuffling when Browser Resized

I used Enfold’s portfolio to creates various lessons on my website. These lessons need to be in a logical order. However, when the browser window is resized, later lessons start jumping out of order. (It seems to start with the seventh lesson.) The weird thing is it only affects the top masonry (Camera Foundations), not the second one (Filtration Series).

http://indiecinemaacademy.com/camera-series/

Settings:
* Masonry (flexible)
* Sortable: No
* Gap: Large
* Overlay: Deactivated

I do use the plugin “Post Types Order” to order my lessons within the portfolio, since I don’t necessarily post the lessons in order. It is possible this plugin is interfering with Enfold’s sorting of portfolio items, but I really doubt it.

Is my problem a result of something I’ve done, or is it a coding issue with Enfold?

Thanks!!!