Did you enter a opening balance? That is quite often the problem why the balance is wrong. If you have entered the right opening balance you can reconcile the account with a uploaded bank statement.
Are those accounts under the same login within barclays? If so, did you grant permission to both accounts when you set them up? Did you setup your bank account and creditcard account as barclays/barclaycard within quickfile?
I don’t bank with them so I can give only general advice