AllowedClasses - Picker is empty

Here’s what my header file looks like:

#pragma once

#include "GameFramework/Actor.h"
#include "MyActor.generated.h"

USTRUCT(BlueprintType)
struct FMyStruct
{
	GENERATED_USTRUCT_BODY()

		UPROPERTY(EditDefaultsOnly, Category = Test, meta = (AllowedClasses = "AMyActor", ExactClass = false))
		FStringAssetReference MyStructAsset;
};

UCLASS()
class MYPROJECT13_API AMyActor : public AActor
{
	GENERATED_BODY()
	
public:	
	// Sets default values for this actor's properties
	AMyActor();

	// Called when the game starts or when spawned
	virtual void BeginPlay() override;
	
	// Called every frame
	virtual void Tick( float DeltaSeconds ) override;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Test)
		FMyStruct StructProperty;
};

As you stated, I created a blueprint based on MyActor. When I expand the dropdown for MyStructAsset it still shows available classes.

Can you post the code you’re using along with a screenshot of what your blueprint details look like for comparison?