This comes from this community discussion with explanation from Ballard Ingram as to the cause/solution:

In my report, I created a text-input field titled "Report Role" with the value of "Student." This helps us filter out user data related to profiles that are just listed as "Student." My client advised that they see everyone, not just "student." This was because the profile field visibility was set as "User, Teachers, and Admins only." It needs to be "visible to everyone." Once I made that change, boom. It worked. The audience was able to see the report I intended them to see.

It would appear that user profile fields that are hidden from users, when added as conditions to a report they are not applied if the user viewing the report cannot see the profile field. This behaviour is unexpected and wrong

To also check: same behaviour with custom fields