Is anyone else have trouble with the stock valuation report not picking up the edited rate of a stock item

I'm glad to see you reaching out to the Community, @rob-still.

I can share some information about the Stock Valuation Detail report in QuickBooks Online. The amounts that will reflect from the Rate column will depend on the cost of your inventory used on transactions.

Please see the sample screenshots for your visual reference:

The only way to update the figures is by recreating the invoices with the updated inventory cost. However, I suggest seeking expert advise from an accountant to ensure any changes will not affect other reports.

For additional information, I've attached an article about how FIFO works and affects your stock inventory: What is FIFO and how is it used for stock cost accounting?.

Please know that the Community has your back if you need assistance. It’s a place for you to connect with experts and peers. Wishing you and your business continued success.