Why I cant insert a List in the WritableArray?

I have a case where I want to insert a List in the WritableArray and send it to React-Native but for some reason, it doesn't work, I don't receive anything back in RN:

public static List<Native_DataList> Native_Data = new ArrayList<>();

The reason why I am using WriteableArray is because that's the only way to transport data from Native to React-Native.

@ReactMethod
public void getData(Callback callback){
    if(!Native_Data.isEmpty()){
        WritableArray nativeArray = Arguments.fromList(Native_Data); //this doesnt work
        callback.invoke(nativeArray);
    }
}

It fails with this error: Unknown value type class com.myprojectname.KeepAliveService$Native_DataList

I am doing exactly the same thing in another case but I am using ArrayList instead and works:

public static ArrayList<String> jsonArray = new ArrayList<>();

And this is the function being called from React-Native:

@ReactMethod
public void getData(Callback callback) {
    ArrayList<String> jsonArray = jsonArray ;
    WritableArray nativeArray = Arguments.fromList(jsonArray);
    callback.invoke(nativeArray);
}

Any suggestions?!