About change localname for bluetooth

I have two app, one as Peripheral and another one is Central.
When I open peripheral app set "CBAdvertisementDataLocalNameKey" = @"123456789012", the Central one can recieve this local name in delegate(centralManager:didDiscoverPeripheral:advertisementData:RSSI:). after i change peripheral app "CBAdvertisementDataLocalNameKey" = @"123",the Central one can't recieve new local name it also be old one. it's some role that i don't know?
About change localname for bluetooth
 
 
Q