Hello there, tacas. Let me shed some light on why your profit and loss are inaccurate and why the balance sheet shows negatives in AR.

A noticeable discrepancy between the Profit & Loss may be due to one or more issues, including, but not limited to, the following:
 

• The date ranges of the reports do not match.
• The accounting bases of the reports do not match.
• Sales items point to incorrect sales accounts.
• The P&L report includes transactions that do not use items (e.g., the Expense Tab on a bill or a journal entry).
• List of transaction damage in the company data file.

Meanwhile, a negative Account Receivable (A/R) results from customers' credits or overpayments. It's also because a specific transaction is charged twice, resulting in double payments. You'll want to run the A/R Aging Summary report to check the associated transactions and review the possible overpayments. 

On the other hand, it's advisable to seek advice and guidance from your accountant to ensure the steps in the video align with the needs of your business. It will also guarantee the accuracy of your financial records, including the proper recording of transactions. If you don't have one, you can find a professional through this link: https://quickbooks.intuit.com/find-an-accountant/.

For future reference, you can set up automated reminders for your customers. This feature can help you get paid faster and reduce the number of overdue payments. 

I'm always here to back you up whenever you require further assistance concerning your QuickBooks profit and loss report and transactions.