File Adapter always creating new file with Old data

Hi Experts,

We are facing a strange problem in PI 7.31. In file receiver we are using file create mode as add timestamp.

But adapter is creating a new file with correct timestamp but it contains new data and also the old data. In every new run file size is increasing.

1st run--> New file with size 200 KB

2nd run.--> New file with size 400KB

3rd run-->600 KB

4th run-->800KB....