You need to figure out which part of your code is corrupting memory. What does VShow() do?
Also, why are you copying the string data? TJsonReader can process the data directly. Create a FMemoryReader archive around the TArray and then create a Json reader from it. Pseudo-code:
FMemoryReader MemoryReader(ReceivedData.GetData());
TJsonReader<> JsonReader = TJsonReader<>::Create(&MemoryReader);