Hello there, @maryskustomkreations. I appreciate you sharing details of what you did in QuickBooks Online (QBO). 

I have replicated the scenario on my end and observed that different item prices (old and updated) appear on my test invoices. Please refer to the attached images for visual reference (Note: Screenshots include dummy information).

It is possible that you modified the item cost before creating the invoices, which resulted in not having different item prices (old and updated). When you adjust prices for Products/Services in QuickBooks, the changes only affect future transactions.

However, if you created the invoice with the old price before adjusting the item cost and still don't see the desired result, this could be a browser issue. 

Browsers use cache and cookies to load web pages faster on subsequent visits, but this can sometimes cause unexpected behavior that affects the views and performance of QBO. To identify the issue, I recommend using a private window, as it doesn't save any temporary files.

To open an incognito window, you can use the following keyboard shortcuts:

• Mozilla Firefox & Microsoft Edge: Press Ctrl + Shift + P
• Google Chrome: Press Ctrl + Shift + N
• Safari: Press Command + Shift + N

If you are able to generate different item prices after adjusting your product's cost in the private window, I’d suggest deleting your browser cache to refresh the system. If the issue persists, I recommend using other supported browsers. This will help us determine if the problem is specific to your current browser.

Additionally, you may want to explore this article to learn how to set up reorder points to keep tabs on your inventory in QuickBooks: Set up alerts for low inventory and then reorder products in QuickBooks Online.
 

I'll be around if you have other follow-up questions about managing your Products and Services. Just tag me in your reply and I'll get back to you as soon as possible.