Heltec Lora 32 V2 + Helium gateway

Hi, I’m having an issue with the code: https://github.com/HelTecAutomation/ESP32_LoRaWAN/tree/master/examples/OTAA_OLED_Interrupt_CLASS_A
I can see on the screen that Lorawan starting but nothing else after that it keeps flashing that’s all! No Uplink or Downlink. Could someone guide me on what I’m doing wrong?