Unable to change manager in "Manager hierarchy"

Hi,

   i am trying to work on "manager hierarchy" i have two user(u1,u2 -same bu & role) are first assigned to the manager Test2. when i tried to change the manager of these two user as "Test1" the record created by u1,u2 aren't reflected in Test1  queue(all record view).

Both manager share the same security role.So based on the hierarchy rule the records should reflect.what am i doing wrong?

is there any technical reason behind this? please help

thanks & regards,