In one of the Org, Custom Profile Users are unable to view other users in org, and there is no "View All Users" flag in Profile.
In other Orgs, Same profile users can see other users even when there is no "View All Users" flag in Profile. Can be config difference in Orgs.
"View All Users" flag is available just for an Admin Profile (Has Modify All and other Admin Privileges) in all Orgs.
Is there any setting/permission which would enable profile users to see all other Users ?