Hi there, marciaw.
Let's fix this odd behavior by running some troubleshooting steps.
To start with, close all the open windows. Then, click the File menu. Under Utilities, select Verify Data. If you see a specific error message, try searching for it on our QuickBooks Desktop support site for specific instructions.
If the system prompts you with Your data has lost integrity, it indicates a data damage file. From there, rebuild the program. Choose File and then Utilities. Then, select Rebuild Data.
For detailed steps in reconciling the transactions, you can check this article: Reconcile an account.
Let me know if you have other concerns with QuickBooks or if you need help reconciling the transactions.
