SharePoint Online Search does not show old documents to the new site user

I use SharePoint Online. I've added a new user to the site, but the search results do not seem to display old documents / list items.

I've tried adding new items / updating old items. Both scenarios appear in the search results for the new user.

It seems that only documents / list items added / updated after adding the new user appear for the new user.

However, I have tried to log in as a former user and I can see the appropriate search results for the documents.

I've already tried re-indexing the site and testing again after 24 hours, but the same result still occurs.

Is this the desired behavior or is there something else I should do?

Thank you