Users With Server Administrator Role (Explorer) do not Show Under All Sites When Site Role Filter is Applied

Steps to Reproduce

1. In Tableau Server with Core based licenses, create multiple Sites.

2. Add a few Server Administrators to each Site and also other Site Roles, like Explorer or Viewer.

3. Click on Manage All Sites > Users
   It will display all the users (including Server Administrator)

4. Click on Filter > Max Site Role and select Server Administrator
   It will not display any Server Administrator

5. Click on Filter > Max Site Role and select Explorer or Viewer

   It will correctly display the list of users.