Zabe, I am glad to see your no-solar system is finally working correctly. Thank you for sharing the whole story!
I am also an SGIP PowerWall owner. In addition to backup, time shifting my grid consumption to off peak times saves me money and also eliminates my the grid draw during peak load times, saving PG&E money and hence all of their customers as well. While I do have solar, I am interested in your story because sometimes I want to grid charge due to insufficient solar, and have posted info about this elsewhere in this forum. However, until your description above, I was never clear on exactly how a non-solar installation functions. So your description answers an important question for me.
For those who posted to this thread who do not know the facts: 1) PG&E and CPUC do allow, and even encourage charging PowerWall from the grid during off peak times. This is, in fact, what TOU rates are for, and why CPUC created SGIP in the first place. 2) Tesla's web site describes how PowerWall without solar is supposed to behave, which is what as the Zabe expected and eventually got Tesla to configure it for.
Anyway, thank you again, Zabe, for posting your story. I'm sorry that your installer and Tesla got it wrong and then took so long to correct their mistakes.
SW