Thanks for writing in!
The portfolio filter only shows the item exist in that page only. Your port folio having a pagination where it only shows 6 items in a page, so when you click on 24小時診所 it filters that category item in the page.
Please so more item in the page so that it will filter more items from that category.
To show more item in the page please edit the portfolio page, set the item number and colum in the port folio section.
Hope this is clear now.