Stop doing this :

using (var memory = new MemoryStream())
{
    using (StreamWriter writer = new StreamWriter(memory, Encoding.ASCII))
    {
        foreach (var lineData in dataLines)
        {
            writer.WriteLine(lineData);
        }
        
        writer.Flush();
        return memory.GetBuffer();
    }
}

Just… do this instead.

return Encoding.ASCII.GetBytes(lineData.Join("\n\r"));

Trust me, it’s not worth using streams unless you explicitly need to.