I've seen this problem now 2 times in a demo of mine. Haven't had time to nail it down yet, but recording a JIRA, as otherwise I'm gonna forget
What seems to happen is that when I start a case that can go from start to end without any wait-states, the CaseData in the CaseFile is not stored in the logs (I think it's VariableInstanceLog). It at least does not show up in the Business Central Process Instances view for the completed process. This is a problem, as it does not allow us to analyse why a case was processed automatically (or do any analysis at all), because we miss all of the data.
This happened on the new CreditCardDispute demo. Will update this JIRA when I have a bit more information and hopefully a reproducer.