I can share a few information about running financial reports in QuickBooks Online, QB Beginner.

When setting the date period for August in the Profit and Loss report, then the bill created in July will not show in the report. This report will only show your income, expenses, and net profit or loss over a specific period.

While for the Balance Sheet report, the transactions you've created for July will show in August statement since it is a cumulative report that carries a beginning balance.

If the transaction you've created is not showing for both reports, you can set the reporting period to all All Dates option. You can also check if you choose the correct Accounting method when running the reports.

An accrual-basis report shows income regardless of whether your customers have paid your invoices and expenses or if you have paid all your bills. While a cash basis report only shows income if you have received or paid expenses in cash.

For more details about missing transactions in Profit and Loss report, you can check out this article: Why Are My Income And Expense Transactions Missing From My Profit And Loss Report.

If the transaction is still missing, you can use the Audit Log feature to see if it was modified or deleted by other users.

I have a link here that contains articles about managing reports: https://community.intuit.com/browse/quickbooks-online-intl-reports.

Please reply to this post if you need anything else with running reports. I'm always here to help.