Arduino NFC P2P Communication

I have an NFC Shield and an NFC Module from elecfreaks and 2 arduinos (one of them is UNO and other one is MEGA). I want to communicate these 2 arduinos via p2p by these 2 NFC. Also I use NDEF library which is: GitHub - don/NDEF: NDEF Library for Arduino. Read and Write NDEF Messages to NFC tags with Arduino.

My examples are same as P2P_Recieve and P2P_Send. But problem is when they try to communicate each other both of them stacks in readResponse function which is defined in PN532_SPI library. Below you can see where it stacks:

while (!isReady()) {
        delay(1);
        time++;
        if (timeout > 0 && time > timeout) {
          DMSG("is not ready\n");

            return PN532_TIMEOUT;
        }
    }

Do you have any idea what is the problem? How can i solve it?