Your credit report is a snapshot of your financial information on the date it's generated. Data is shared with credit reference agencies (data providers), by lenders (data owners). This takes time so your report can be at least 5 weeks out of date.
To see your balances in real-time please check with your bank or providers.
If you have an overdraft on your current account and it's showing as £0 balance on your credit report. This means the overdraft wasn't used at the time the bank or provider shared this information.