Looks like both of them show up at the direct links (e.g., Impact of Immigration, Segregation with Social Linkages) which is a good way of checking if something didn't get deployed correctly. There also aren't any errors in the build and deploy log which is a good sign. So it's likely something in the code of the pages themselves.

It took me a bit to see it, but the source for Cerqueti-DeBenedictis-LeoneSciabolazza_2022.md has a typo in the category field which will prevent it from matching any of the categories defined in _config.yml. As for the other one, I might be missing something, but it seems like it's the second entry from the top of publications?

Also, I should update the Wiki to make this clearer, but you can add new publication_category beyond just the three that are defined by default - the new category would just need to be structured like the others, e.g.,:

publication_category:
 books:
 title: 'Books'
 manuscripts:
 title: 'Journal Articles' 
 conferences:
 title: 'Conference Papers'
 preprints:
 title: 'Preprints'