All the info entered from April to August has vanished.

Hi there, @pc57.

Filters can be the reason why some of the entries are missing. Let’s open the Transactions menu and change the Type, Account, and Date drop downs to All to verify.

 Here’s how:

1. Log into QBSE and click the Transactions menu.
2. In the Type, Account, and Date drop-downs, choose All.
3. Scroll through the list of transactions to see all your entries.

If you’re unable to find them, I recommend downloading a copy of these transactions from the bank using a CSV file. Once done, import it to QuickBooks. 

 Follow these steps: 

1. From the Gear icon, select Imports. 
2. Select the bank account and click Import older transactions in the Action column.
3. Follow the succeeding steps to import the file. 

Take a look at this article for the details: Import transactions from other sources.

Please let me know in the comment section if there's anything else you need. I'm here to keep helping.