Hi, 
So I’m enjoying the Home Automation course, which I must say is very well done. 
Unfortunately I’m struggling with getting a Sonoff switching from the Node Red dashboard. A Debug window shows that the output text string is being published as “on/off” but the relay doesn’t switch. 

• My RPI has a brand new image of Rasbian Stretch (no security) 
• Node Red works fine in all other lessons
• The Arduino sketch seems to load no problem (modified with SSID/Pwd/MQTT IP Address
• The same Sonoff flashed with Tasmota works fine (from the web server)
• A D1 Mini with the “Hello World” sketch loaded also failed to deliver anything to the Node Red dashboard. 
• Following Dr Zzs Tutorial I tried to use Tasmota via Home Assistant with similar none functioning dashboar

So Im at a loss. The hardware has proven to be functional (tried a different unit for the sake of my sanity)
Any ideas?? Or advice on troubleshooting tools? 
Warm regards 
Paul