Bank accounts not reporting correctly

After upgrading both of my companies to V12.0, I have found a minor problem. The ‘Bank Accounts’ summary page does not seem to be updating with the correct balances. The balance is correct for each account when I view it for the account, but the summary screen seems to be reporting an old value.
The main (home) dashboard does seem to be reporting the correct balance however.
This was not an issue with V11.0.4