When you corrected the Product/Service information, the changes will only affect your future transactions, Phoenix2. Unless, you marked the Also update this account in historical transactions box.

Let's edit the item and toggle the affected account:

1. In the Products and Services page, look for the affected item and click Edit.
2. Change the affected account and click Save and close.
3. Click Edit again and correct the affected account.
4. Mark the Also update this account in historical transactions box.
5. Click Save and close.

Then, you can go back to the Profit and Loss report. This should refresh the data you have on file.

I'll be right here if you need anything else.