search function sharepoint site

Hi all! 

At the office we ( a colleague and I ) recently set up a Sharepoint , consisting of around 12 hub sites . We are both owner of the 12 sites

Some of the hub sites are set to public group, others are set to private group depending on the content and the authorization of the person

The problem that we encounter is , that on 5 of the hub sites, the search function does not work for us but on the other hub sites , we have no such problem.

The strange thing is that I checked with some other users in our office and they don’t seem to have this problem, so the search function for all hub sites does work for them.

I do not have a clue yet .

note : we don't have admin rights! 

Thanks in advance !