Change member variable with type of struct in BluePrint

[yateam]

Hello, It seems I stuck with my problem. Looking for some help.
I have a pawn class. Here is its structure:

UStruct(BlueprintType)
struct FWeaponSlot
{
    GENERATED_USTRUCT_BODY()

    UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Weapon)
    UWeaponComponent* Weapon;
}

class ATank : public APawn
{
    UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = Weapon)
    FWeaponSlot WeaponSlot0;
}

Now I expect that I can extend ATank in Blueprint and create different kind of tanks. That works fine until I get to the point where I need to set the weapon component. In BluePrintEditor all I can see is a combobox with only one option : WeaponComponent. However, I created a few more blueprints which extend WeaponComponent

As you can see the dropbox contains only one value.

What could the problem? WHy the dropbox does not see other weapon components?

Thanks