Hi dijo,
Welcome to the Community!
It's important that you start by checking what the figures displayed on your inverter represent. It's likely that your software is showing you all of the energy your solar system has generated, where as your online AGL account will only show you the quantity of energy you've exported to the grid. The difference between these two figures is the amount of power you've used within your property.
I encourage you to double check this and please let me know if you have any further questions!
Kind regards,
Jayden