The feature to sort portfolio articles by category does not work.

Question

I copied and pasted the source code of portfolio-5.html, which I got from a package generator.
However, the feature to sort portfolio articles by category does not work.
Even though I click some buttons such as "Show all," "Illustrations," "Icons," and "UI Elements," the page URL becomes "#," and the articles are not sorted.
I copied the  section on the footer and CSS too.
Why the function doesn't work?
The below is an example that the URL becomes "#" and the sort function doesn't work.
https://www.asc.co.jp/test/plan04/index.html
Basic authentication
ID; asc
PW; test999
Thank you for your support.

idealism · Answer

I realized I used the same ID class in header navigation and a content area. Sorry to bother you, but I could solve this problem. Could you please close this ticket? Thank you.