c++ Can read but can't write on IOS, Does someone has a solution?

Can´t write nor append for my life a file in an Iphone, even though when doing the same process on Android I could do the same without any further problems. Also, I’m able to read without problems. Using 5.2, both blueprints and c++ code, in this one the FFilehelper library, with the function SaveStringToTile.

Header Content:


#pragma once

#include "CoreMinimal.h"
#include "Kismet/BlueprintFunctionLibrary.h"
#include "RWtextFile.generated.h"

class FJsonObject;
/**
 * 
 */
UCLASS()
class MYAPP_API URWtextFile : public UBlueprintFunctionLibrary
{
	GENERATED_BODY() 
public: 

	UFUNCTION(BlueprintCallable, Category = "ReadWriteFile")
		static FString ReadStringFromFile(FString FilePath, bool& bOutSuccess, FString& OutInfoMessage);
	UFUNCTION(BlueprintCallable, Category = "ReadWriteFile")
		static void WriteStringToFile(FString FilePath, FString String, bool& bOutSuccess, FString& OutInfoMessage);
	UFUNCTION(BlueprintCallable, Category = "ReadWriteFile")
		static void AppendStringToFile(FString FilePath, FString String, bool& bOutSuccess, FString& OutInfoMessage);
	
	

};

.cpp content:

#include "RWtextFile.h"

#include "HAL/PlatformFileManager.h" // Core
#include "Misc/FileHelper.h" // Core

FString URWtextFile::ReadStringFromFile(FString FilePath, bool& bOutSuccess, FString& OutInfoMessage)
{
	// Check if the file exists
	if (!FPlatformFileManager::Get().GetPlatformFile().FileExists(*FilePath))
	{
		bOutSuccess = false;
		OutInfoMessage = FString::Printf(TEXT("Read String From File Failed - File doesn't exist - '%s'"), *FilePath);
		return "";
	}

	FString RetString = "";

	// Try to read the file. Output goes in RetString
	if (!FFileHelper::LoadFileToString(RetString, *FilePath))
	{
		bOutSuccess = false;
		OutInfoMessage = FString::Printf(TEXT("Read String From File Failed - Was not able to read file. Is this a text file? - '%s'"), *FilePath);
		return "";
	}

	bOutSuccess = true;
	OutInfoMessage = FString::Printf(TEXT("Read String From File Succeeded - '%s'"), *FilePath);
	return RetString;
}


void URWtextFile::WriteStringToFile(FString FilePath, FString String, bool& bOutSuccess, FString& OutInfoMessage)
{
	// Try to write the string into the file
	if (!FFileHelper::SaveStringToFile(String, *FilePath))
	{
		bOutSuccess = false;
		OutInfoMessage = FString::Printf(TEXT("Write String To File Failed - Was not able to write to file. Is your file read only? Is the path valid? - '%s'"), *FilePath);
		return;
	}

	bOutSuccess = true;
	OutInfoMessage = FString::Printf(TEXT("Write String To File Succeeded - '%s'"), *FilePath);
}

void URWtextFile::AppendStringToFile(FString FilePath, FString String, bool& bOutSuccess, FString& OutInfoMessage)
{
	// Try to write the string into the file
	if (!FFileHelper::SaveStringToFile(String, *FilePath, FFileHelper::EEncodingOptions::AutoDetect, &IFileManager::Get(), EFileWrite::FILEWRITE_Append) )
	{
		bOutSuccess = false;
		OutInfoMessage = FString::Printf(TEXT("Write String To File Failed - Was not able to write to file. Is your file read only? Is the path valid? - '%s'"), *FilePath);
		return;
	}

	bOutSuccess = true;
	OutInfoMessage = FString::Printf(TEXT("Write String To File Succeeded - '%s'"), *FilePath);
}