remote control won't synchronize drone

Hi,

I have just got two new Protocol Evo SlipStream.

First one is working fine. But second one has synchronization problem.

Here is what i did to sync:

1- Connect battery cable to drone to turn it on

2- open remote control

3- a couple of up-down with joistics.

The on the drone stop flashing in a couple of seconds. But the led on the drone always flashing.

Do you have any idea, what it could be the reason?