Serial input doesn't refresh

[Tom92 (Tom Janssen)]

Hi,
I thought that I fixed mine problem (see the link below).

Serial sensor doesn't work anymore

Oke I fixe it with this: Using serial sensor for reading JSON output from Arduino? You need to put this: Serial.println('\n'); on the end of you’re Arduino sketch. I wondering why tis first worked but very happy that it worked yet.

But it is not true.
Wenn I plug the USB cable in de data is refreshed but does not refresh any more.
When I take the cable out and in again the data is refreshed.
Why does the serial sensor refresh anymore?