Non-Admin Users Show that They Still Have Access to the Sandbox Account After a Sandbox Refresh

Although the Give Access checkbox is checked on the non-admin employee record, if the non-admin tries to login, the user won't be able to.
  

An enhancement has been filed for this.

Enhancement 224464 : Sandbox > When a Sandbox is initially provisioned or a customer requests for "Admin Only" Sandbox refresh. > All non-admin users record should have "Give Access" box unchecked.