Found today that auto-discovery wasn't working for iRFR (I knew that the network was OK as I could still connect manually)
Upon investigation I found that if I turn off cellular data the connection worked. For my own app I needed to fix this and realised that I need to define the interface for the broadcast messages to attache to - I used en0 and all worked fine. I think it may be an apple watch issue as I didn't have this issue until I got an apple watch