OTAA join problems - Australia

The TTN console sees my Pycom Lopy4 device connect (status = green light) but lora.join never returns True.
I’m connecting to a Multitech Conduit Gateway in my area using OTAA on AS923
Lopy4 details
(sysname=‘LoPy4’, nodename=‘LoPy4’, release=‘1.20.1’, version=‘v1.11-12f4ce0 on 2019-10-06’, machine=‘LoPy4 with ESP32’, lorawan=‘1.0.2’, sigfox=‘1.0.1’, pybytes=‘1.1.2’)

My code
I have posted on the Pycom forum, but no response.
Grateful for any help.