I'll help you fix this right away, @tidybison. There's a way to upload transactions manually if you can't download them from the bank automatically. Let me teach you how if you haven't tried it. I'll show you how to do it in QuickBooks Online.
When you delete your old bank account, it also removes all your transactions from last year. To recover these transactions, you may need to restore the old bank account or re-import the transactions from your bank. If you have a backup of your data, you can also use that to retrieve the deleted transactions.
Moreover, when uploading transactions manually, you can select specific files from past to newest transactions and add them to QuickBooks. If the file is too large, you sort it or shorten the date range to smaller groupings, since QuickBooks Online accepts 350 KB per uploading session.
Refer to this procedure of manually uploading a transaction in QuickBooks Online.
Go to the Banking tab; select the Banking section.
Select the blue tile for the account you want to upload the transactions.
Select Upload from the file.
Select Drag and drop or select files and select the file you downloaded from your bank. Then select Continue.
From the QuickBooksaccount▼ dropdown, choose the account you want to upload the transactions. Then select Continue.
Follow the onscreen steps to match the columns on the file with the correct fields in QuickBooks. Then select Continue.
Select the transactions you would like to import. Then select Continue.
It's always been a pleasure to have you here, @tidybison. Let me know if you have other matters in the banking section. The Community still has your back. Stay safe!