horace:
can you check DIO1 with an oscilloscope of a multimeter?
are you attempting Lora peer-to-peer communications or LoraWAN - if the latter does the backend show uplink data has been received?
I just checked and DIO0 is always high (3.3V) and DIO1 is Low (0V) after initialising. I am just using peer-to-peer communication.