Problems communicating with 2X Nano and 2X nrf24l01

r2m:
I saw many people connecting miso mosi and sck to 11, 12 and 13, but I wanted them on 4,5 and 6 and so, I changed rf24_config to use these ports.

Since you have no clue what you are doing, why did you think you would change them to 4,5,6 ?