Cannot set Simulate Physics in BP Editor, but can in World

I have a C++ Pawn class that configures the StaticMeshComponent:

StaticMeshComponent = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("StaticMeshComponent"));
RootComponent = StaticMeshComponent;

Which is sub-classed in a Blueprint in order to configure the actual static mesh. This static mesh has a collision mesh and default collision profile of Pawn:

Note, however that the blueprint editor is showing what I can only call a cutdown version of the details pane and I am unable to set Simulate Physics and set things like Mass. When I drag this blueprint into the World, however I am able to set these things, and I get a more complete Details pane:

Can anyone suggest why this is the case? Given the pawn is created via a Player Start Actor and not configured directly into the World, then I want to be able to set the physics params.

Any help appreciated.

As an update to this question, I have solved the issue by removing the creation of all components in the base C++ class and I create them all in the blueprint subclass. If I want to hook in any collision callbacks in the base class, I do that in the ABasePawn::PostInitializeComponents() method.

Is this a bug in the engine, or am I forgetting to set something in the component when creating it from the C++ class constructor?