APM SSO Between NTLM and Forms Based

Update:

I was able to get SSO logging working by creating a new logging profile with SSO logs set to debug mode and attaching it to the Form-Based Configurations I had set up. This allowed APM logs to capture all SSO-related activity. After reviewing the logs, it looks like the issue may be related to how the forms page is designed. The page is driven by multiple JavaScript scripts, which also generate session-based request attributes for the ASP.NET framework on the server side. For some reason, after parsing the page it never submits a POST request as expected, though it’s not entirely clear why this happens.