Hi,
problem with your guide is that he interfaces Modbus which is reserved by the Eastron Smartmeter. You cannot have 2 Masters on the Modbus network. The inverter and Smarteter are very busy communicating (every few ms) and it is impossible to get between the pollings without interference.
I opened another thread with an approach that uses the cloud API:
Unfortunately I have not got it running yet. Maybe you are more experienced in that. Let me know if you have a solution.