Yes, indeed, we do not allow changing the flow type via the user interface for good reason - the flow type influences how a flow can be used in modeling, and if you change the flow type, this of course applies everywhere where the flow is used. Thus, to the question, I wonder why and how this has happened if not by executing some code (SQL or other), or by having created the same flow twice, with different types, and if you have no clue, then I would not execute additional code. It is also not "properties" of the flow but it is its type.