How to Edit Filter Animation?

We have Post Grid up and running and working great, but we have a problem with the animation when clicking a filter category. Sometimes we get a second animation after the new posts grow into the grid, where it will then slide in from the left. An example is on this page when clicking on the Governence filter:

http://www.thecenterforcharters.org/view-all-past-events/

Any ideas? Thanks.

https://ww.wp.xz.cn/plugins/post-grid/