Hi ,
The time taken in this case can be due to the device config profile which is getting targeted . The device profile needs to be completely succeeded in order to apply the kiosk profile because that is the only one which is initiating the device to kiosk mode. When you need to make an immediate check-in with Intune service you are calling the device sync API which will be ultimately checking the policies targeted on the devices and applying them accordingly . what my understanding says is that the device will take some time in order to process the policies which are targeted and sometimes it varies with the network on which which we are performing the things.