When I click on a customer it no longer shows their invoices, how do I turn that back on?

Hi, there @frontdesk5,

You can check the audit log to view if the invoice transaction was already been save. Follow this on how to use audit log:

1. Go to the Gear icon.
2. Under the Tools, select the Audit log tab.
3. Click the Filter button.
4. For the User field, select All Users.
5. Filter the date range when did you create the invoices.
6. On the Events, choose Show only these events.
7. Put a checkmark in the box beside the Transactions.

Once done, check your invoices if it's in the audit log statement. If not, your invoices are not yet saved. If the invoice transaction is on the audit log, you can click the View button on the invoice section to expand the view and check the invoice.

Also, you can read this article to pull up invoices report due on a specific day in QuickBooks Online.

If you need further assistance, feel free to leave a message in the comment box. I'll be happier to help. Have a good one!