Why does the robot simulation contain artifacts on Android build?

For a Robou simulation I use a csv file with data. I read data as follows:

string dbPath = ""; string realPath; // Android string oriPath = System.IO.Path.Combine(Application.streamingAssetsPath, "Data.csv");

         // Android only use WWW to read file
         WWW reader = new WWW(oriPath);
         while (!reader.isDone) { }

         realPath = Application.persistentDataPath + "/db";
         System.IO.File.WriteAllBytes(realPath, reader.bytes);
         dbPath = realPath;
         using (StreamReader sr = new StreamReader(dbPath))
         {...}

In the Unity Editor version the simulation works as expected but on Android the arm ofthe robot moves in a strange way as you can see in the videos. I compared the two db files (on the Windows and Android paths) and the content is identical. What could be the reason of the strange movemenz?

Editor https://streamable.com/7z4qob Android https://streamable.com/rv4nm2

Thank you!