Welcome to our forum.
This is really unexpected, sorry for the delay,
you should set “Posts per page” = -1 for filterable style grid.
And “Pagination type” = jQuery pagination
Filterable style grid need to load all post on page load
And you will see the option under “Filterable” tabs “Number of items per page” you can set custom number, you see only 3 post for this option. you can increase this value to display more post and rest of the post will be accessible via pagination.
Search feature with filterable style grid isn’t available right now.