Apologies for the delayed reply!
As you've provided us with your account details here in the past, I've been able to make some changes to your online account that I believe may have resolved this issue. Would you mind clearing your cache (instructions here) and then attempt to access your solar export data once again using the screen you've referenced above?
Finally, I can see what others with solar can see when they go to their usage page.
Not sure who to thank as after some three and a half years and dozens of repeated requests for help that were lost in the system or shut down without resolution and seeing that the current attempt was looked into by no less than 4 different people either from AGL or this community.
I will say thanks but you'll understand if I don't get terribly excited about it.
I am totally mystified as to why it was so hard to get this fixed. After 35 years in I.T., if I treated my customers like this . . . I wouldn't have had any of them for long.
The simple fact for me is that an independent bill analysis showed that the cheapest electricity deal I can get is the one I am on, otherwise I'd have been another energy provider's customer after the 2nd time AGL failed to resolve this issue some 3 years ago.