Do missing transactions (date range) from connected bank account last year exist in backup? Or will they have to be entered manually?

I can share some information on why your QuickBooks balance doesn’t match with the bank balance, @rabundoctor.

The QuickBooks balance is the total balance of all bank transactions that you’ve added or matched to QuickBooks. While the data on the Bank balance depends on the added or matched transactions, and what your financial institution shares with us. Yes, you'll need to enter all your transactions from your bank to QuickBooks to match it. 

The amount of data that can be pulled up from your bank account depends entirely on them. If they can provide 90 days worth of transactions, then you can manually add those transactions beyond that through the WebConnect process. 

You’ll have to manually download the transactions from the bank. Then, upload the file to your account.

Download bank transactions:

1. Go to your online banking account to get your file.
2. Check or follow your bank’s instructions to get a copy of the data and then save it on your computer.
3. Ensure that the data range is at least one day before your oldest transaction to avoid duplicates.
4. Please take note of the supported file format and size. It should be either a Comma-Separated Values (CSV) or a QuickBooks Online (QBO) file. 
5. Download your transactions and save the file to your desktop.

To upload the file to your QuickBooks account: 

1. Go to the Banking menu and select the bank where you’re uploading the transactions from the Banking tab.
2. Click the Link account drop-down and select Upload from file. 
3. On the window that appears, click the Browse button and choose the file that you’ll be downloading. 
4. Click on Open, then Next.
5. Follow the onscreen instructions. Match the columns on the file with the banking fields in QuickBooks, then select Next.
6. Click on Let's go. QuickBooks will now add the transactions to your account.

Check this article for more information about adding your bank transactions manually: Manually upload transactions into QuickBooks Online. 

After adding your transactions, you can now match and categorize those transactions and reconcile them to ensure your books are accurate and there aren't any duplicate transactions:

• Categorize and match online bank transactions in QuickBooks Online
• Reconcile an account in QuickBooks Online

If you have other questions about adding your bank transactions, I'm happy to answer them for you. Just post it here as a reply and I'll take a look at it. Have a good one!