Portfolio Grid's "Load More" doesn't work

When portfolio grid settings’ “number of items” are set to show a number of items (say 6) less than the total portfolio items that exist (say 18), the “load more” button doesn’t show any more items, it just repeats the original 6.

Then when in the portfolio section a category is selected that has multiple items, the sorting only shows any of the original 6 that showed up in the “all” tab, that are tagged for that category. There is no way to see the other 12 of 18 items.

I can’t find any settings that would fix this… I am wondering if this is a bug, if I’m missing something, if there is a theme error…