Problem with idletime

I was trying to combine some plugins like Afk Mover, Mass Mover and Mass Message.
While I was testing the parts for the afk mover I noticed that the CLIENT_IDLE_TIME of all client is always 0.
I also tried using requestClientVariables before using getClientVariable, but it is still 0.
I tested other properties like CLIENT_NICKNAME, CLIENT_VOLUME_MODIFICATOR, CLIENT_INPUT_MUTED, CLIENT_OUTPUT_MUTED and it worked normally for all of them