Solved

staff didn't got changed

bought a cd, changed the attribute to spy, changed the cd jus a min ahead of race but was not getting changed.
tried twice.
now unfortunately the attribute which i selected to spy is the weakness of old cd and i'm going to waste the spying change in my first rave itself
edit 1
jus a min ahead of race = jus a min ahead of race was locked

"Next race", "Cars" and "Staff" tabs are locked 10m before the race.

yes i tried 11 mins before the race start time