[Update as of April 3, 2019, this issue has been resolved in the recent LCS release on April 1, 2019]
Recent system updates to the LCS Support flow framework have prevented some questions from displaying for the Incident details steps when a support case is created.
The missing questions are Problem type, Problem area, and related sub-questions. However, this does not prevent users from submitting a support case.
We are actively working to resolve this issue and will update the blog post when this issue has been mitigated with a release.