Load More Post FlexSlider Error

When I load more post on a grid the flex slider does not update and re-contain the next set of post loaded with a flex slider as the feature. There is strange functionality here – sometimes it works and sometimes it does not.

Steps:

1. Open URL
2. Load More Posts
3. Resize window
4. load more

https://zamartz.com/blog/fashion/

each of these steps gives strange issues.