FRDM-k64F not connecting

[sorny92]

I'm using a FRDM-K64F and a RFM95W (SX1276)
I made the minimum configuration but when I run the program it gets stuck in this part.

Mbed LoRaWANStack initialized                                                  
                                                                                
 CONFIRMED message retries : 3                                                  
                                                                                
 Adaptive data  rate (ADR) - Enabled                                            
                                                                                
 Connection - In Progress ...           

I suspected that maybe the connections were wrong so
I tested changing the Activation Method to ABP and then it sent messages, I could see the Gateway getting the messages but the messages would not get to the TTN application.

As gateway I'm using a simple RPI+RFM95W as single channel gateway.

[ciarmcom]

ARM Internal Ref: IOTCELL-2467