I commend you for identifying the cause of the imbalanced quantity of your inventory item through your reports and screenshots you've provided above, @DanOR. 

You're able to correct the inventory and asset values on your reports (Inventory Valuation Detail and Summary) by manually adjusting the item's quantity. With this, you'll have an accurate number of stocks without recording a purchase or sale. The process will automatically record appropriate adjustments to your stock Asset and Cost of Goods Sold (under stock Shrinkage) accounts.

Inventory adjustments can be a tricky process since it can greatly impact your accounting records. With this, I'd also recommend consulting your accountant for further assistance. Once ready, here's how:

1. Go to the + New button.
2. Select Inventory qty adjustment.
3. Enter the Adjustment Date.
4. In the Inventory adjustment account drop-down, select the appropriate account.
5. Select and/or fill in all the necessary details.
6. When you're done, select Save and close.

I've attached a screenshot below that shows the last four steps.

After that, compare the two inventory reports (Inventory Valuation Detail and Summary) again and see the update.

Additionally, there are a variety of reports where you can get helpful insights on the things you buy and sell and the status of your inventory. You can learn more about this through this article: Use reports to see your sales and inventory status. Then, you can customize them to focus on the details that matter the most to you.

Please let me know how it goes. Feel free to leave a comment below if you need anything else or follow-up inquiries about managing inventory items and accounts in QBO. I'm just around to help. Keep safe always, @DanOR.