AddExpectedError not detecting Error from UEngineSubsystem derived class

I’m writing automation tests for a class UMyClass that inherits from UEngineSubsystem. I want my test to catch an error message when I run UMyClass::PrintError(), but it doesn’t seem to work. Here’s my class:

UCLASS()
class MYPROJECT_API UMyClass : public UEngineSubsystem
{
	GENERATED_BODY()

public:
	void UMyClass::PrintError()
	{
			UE_LOG(LogTemp, Error, TEXT("ExpectedError"));
	}
};

and here’s my test:

	{
		UMyClass* MyClass = NewObject<UMyClass>();

		AddExpectedError("ExpectedError");
		TelemetrySubsystem->SendTelemetryEvent(TelemetryEvent));
	}

When I run this, the error prints to the log, but the test fails. I do not have this problem for non-UEngineSubsystem classes!