Issue in data loading after migration of a Data Source from 3.x to 7.x

After migrating one data Source from 3.x to 7.x in development system,I am facing one issue.

When I am tying to load data ,the data records of the 4th filed and 5th field are overlapping.

Customer 2nd Field 3rd Field 4th Field 5th Field 30905919 20160707 57024 6 444000 30905919 20160707 57053 52 468000

In is production,the data source is still in 3.x version. And the same file is loading perfectly in 3.x flow in production system.

But in Development system,the data source is in 7.x version,so we are facing this overlapping issue there only after migration.

can anyone help me?