EspruinoHub crashes when gettingServices while writing from node-red

Hi Gordon,
I have built a new Pi3 installation with node at 4.7.2 and npm at 4.0.5 and tried both versions of EspruinoHub on github, yours and @dklinkman and tested on two Pucks, one at 1.9 and the other the latest beta from yesterday and I still get time out errors:

MQTT>/ble/write/c6:62:41:ed:7f:9a/nus/nu­s_tx => "LED1.set();\n"
Service 	6e400001b5a3f393e0a9e50e24dcca9e
Characteristic 	6e400002b5a3f393e0a9e50e24dcca9e
<Connect> Connected. Getting Services...
Scanning restarted...
Scanning restarted...
Scanning restarted...
<Connect> Timed out getting services. Disconnecting.
BLE broken? No advertising packets in 10 seconds - restarting!

Sometimes it connects, but mostly it fails. I am running out of things to try. Is there any debug info available to get to the bottom of this?