I’m running TTN_TTGOLoRa32_OTTA from https://GitHub.com/fcqdam/TTGO_LoRa32.
Apparently this code does not set the SPI pins, but uses the pins from the selected board. Be sure to choose Heltec_WiFi_LoRa_32 for the TTGO.
Also make sure you use an updated lorabase.h for Australian frequencies and put both #define CFG_us915 and #define CFG_au915 in config.h.