I appreciate you for bringing this concern here in the Community, @DRM.
Once your bank account is connected, the system automatically creates an opening balance. The amount is based on the real-life bank account. The customization features at this time include adjusting and picking date ranges for the information you'd like to see.
As a workaround, you can go to the Banking menu and Chart of Accounts to track and compare both balances.
I've included an article that will help you manage your downloaded bank transactions in QuickBooks Online:
You can always find me here if you have any other concerns or further questions about online banking. Stay safe.
