I made a test project with some task containing fixed cost only, resources only and both fixed cost and resources in order to understand the way it works.

When I have tasks with only fixed cost, summmary activity receives correct values both in remaining column and fixed cost column. Cost column show fixed cost correctly and roll up tasks to its summary task.

When I have task with only resources, summnary activity receives correct values both in Cost Column and Remaning Cost Column.

When I have Task with both resources and fixed cost, Cost column shows the sum of fixed cost plus resource cost, but roll up is only for resource cost, and total cost for project do not include fixed cost. Fixed cost summary activity do not receive information from fixed cost and total fixed cost is not representing the correct amount amount. The Remainng Cost column does not show the correct amount of Fixed Cost plus Resources Cost

If you visit the Project Information window, you can verify the total cost of the project correctly.

Does any one had this kind of behavior? It seems like a bug

Thanks