[4.17.2] Why does my value not reset to default when I click Reset to Default?

In the editor, there is a little yellow icon next to every variable in every blueprint.
As I understand it, I can click that icon and reset the variable’s value to whatever the default value of that variable is supposed to be.

In C++ I setup a bunch of custom UStructs, and setup the defaults as shown in the example below:

USTRUCT(BlueprintType)
struct FExampleData
{
	GENERATED_USTRUCT_BODY()

	UPROPERTY(EditAnywhere, BlueprintReadWrite)	FString		Name;
	UPROPERTY(EditAnywhere, BlueprintReadWrite)	float		Value;
	
	FExampleData()
		: Name("NULL")
		, Value(-1.0F)
	{}
};

In the editor, the Value equals 0.0

If I click the Reset to Default icon, the value remains 0.0

If I set a new non zero value, then click the Reset to Default icon, the value becomes 0.0

I can even manually set the value to -1.0, and if I then click the Reset to Default icon, the value becomes 0.0

Why does the value not reset to the desired -1.0 as set in C++, and how can I force the editor to do so?