I now know what the problem was. I had this bit of code added in my wp-config file so that I would have a different landing page in every user's profile page. After deleting this code, I was able to see different profiles... But thanks for thinking with and for me, Alex.
Enjoy your evening. :) (You can close this topic)
/**
* Change BuddyPress default Members landing tab.
*/
define('BP_DEFAULT_COMPONENT', 'dashboard' );
Thanks for confirmation, closing this topic as your issue was resolved.