I'll start off with saying that I'm going to open a support case on this as well but wanted to put it out here as well.
I've hit a case where a SAM admin created a new template, built out the components for it, assigned it to a ~100 nodes, and then deleted the template. I am now unable to remove the orphaned monitoring instances as they don't show up anywhere in the UI that I can find except on the node page. When I attempt to select the Application on the Node page, I get an error message that says "Unexpected Website Error Object reference not set to an instance of an object." Does anyone have any ideas on how I can remove them? I have confirmed they do not show up within the application monitor list within SAM settings. I have also confirmed that I can't just remove them from the database as it generates an error "Dynamic SQL generation is not supported against multiple base tables".