Why does the account history report in MT4 not show the full history?

To see the full history right-click on the section ‘Account history’ and select ‘All history’ or set the specific history period you would like to see. Keep in mind that the trading history for Cent and Cent NDD accounts is limited to one month and for Classic accounts, six months.
A full trading history can be checked in the Trader Room by going to ‘My trading’ –> ‘Account History’. Specify the range of the account history you want to see and click on ‘Show Statement’.