Hi. I'm able able to view any of the lists I've created in HubSpot, withing the Divi Opt-in module. The lists are passive and have both "Forms" or "Subscriptions" as filters. I am not getting error when I entering my account and API (Private App) key. Additional info is that the Hubspot plugin is installed and connected and the Non-Hubspot Form integration in turned ON.
Below are the images of the Integration API, Divi Module and Lists