Can't go to page 2 of categories post

Hi all

this is my live staging link
https://staging.careermums.com.sg/category/resources/

if you scroll all the way to the bottom, there is a page 2 which will link you to

https://staging.careermums.com.sg/category/resources/page/2/

and for some reason it isn’t working. Even if I de-activate the wp-pagenavi plug-in it will not work, the pages just simply refuse to load.

Any idea what went wrong?