I am having trouble using the LTI deep linking flow to create materials for my course. Our app has been added as an external tool with LTI Deep Linking enabled. Using the Materials > Add Materials > [Our External Tool] menu, Schoology sends the expected request and launches our external tool to select an item. When we select an item, our tool submits the required data as per the spec (https://www.imsglobal.org/specs/lticiv1p0/specification). Schoology briefly shows a little loading graphic, the page reloads, and nothing is showing in our Materials list. Our tool is returning an LtiLinkItem content item so I am expecting some sort of launch link assignment to appear in our Schoology Course’s Materials list.. there is no error reported by Schoology. I am using Chrome. Does anyone have any ideas on what I can do to get this working? Thank you!