Thanks, but you didn't read my post.  I'm fully aware of what FIFO is and that is why now, years after the bogus entry that was made in 2018, this issue is surfacing.  i.e QBO has been pulling the oldest stock first and finally has "gotten to" this entry that effectively adjusted the value of inventory and unit cost.  If you read my post, you'd see that the error was made in 2018...not going to reopen the books and restate the prior financial statements to correct the orginal transaction.

The answer is:  QBO does NOT have the capability of adjusting the value of existing inventory items...only the quantity.

The only solution is to:

1.  Delete all the sales estimates and invoices using this product code since the beginning of the year.

2. Then delete all inventory on hand at 1/1/2021, charging it to "inventory adjustments"

3. Then create a new temporary part number and add back the quantity on hand using the correct value at 1/1/2021, hopefully being able to book this to the same "inventory adjustments" account so they offset each other, leaving the net effect of the correction in this account.

4.  Then , recreate the estimates and recreate the invoices using this new temporary part number.

5.  this should result in 2021 P&L and inventory accounts being properly stated.

Now...what we have to figure out is how to go back to using the "real" part number for future purchases and sales. 

QBO is worthless when it comes to inventory management and accounting.  It's absurd that we have to spend hours on what should be a simple single entry.