They have known for years that you can't adjust the value of stock items in QBO, and there's no sign Intuit will ever fix it. There is no point in you submitting a feedback request via the cogwheel, as they will ignore it. 

What sort of accounting package doesn't let you amend stock value?! QB Desktop, which they have discontinued in the UK, was able to do it.

Therefore, I now have to spend countless hours entering data in to spreadsheets to do the calculations for the year end, which I then need to reverse and recalculate the following year. More work, and more chance of errors.

This is just one of QBO's many shortcomings.

QB Online is a really pisspoor product.