If You are wondering, why You can't reproduce the score from Starter Notebook, it is because both Train and Test are different, Starter(7242/2920 records), Official(7744/2418 records). Totals are the same 10162 records, looks like there is just a shift of 502 records.
I think you will still get 1057 with the starter notebook's code even with the shift in data.
Are you using the starter notebook code?