Expanding Content - Masonry doesn't trigger

I am trying to use Masonry API, Masonry Views and Views Fieldsets together. I have Masonry working and Masonry Views.

Views Fieldsets provides a fieldset for collapse/expand content: https://www.drupal.org/project/views_fieldsets →

When you expand the content, the Masonry View doesn't adjust to the expanding content. The expanded content just goes under the other grid items.

I have been investigating and wonder if you need to trigger Masonry as you do when the browser resizes. Is this correct? If so, does anyone know how this can be done?

I imagine this is the same for anyone who has hidden divs/fieldsets which get displayed when clicked.

Thanks