Now I think that you need to go into Essentials and create a new Integration user with full permissions, then use that username/password in the plugin device. I had a similar problem when I upgraded to the latest version of Inclusive (12.7.0).
I created a new user but could not see how to bring over my existing data.
In the meantime, I removed and recreated the gateway in Indigo and now can not activate the gateway. There are messages about the telenet connection being closed.
Sorry to bug you