I built a inventory activity detail with the following filters: Posting is T Tax Line is false shipping line is alse Item type is inventory Account is inventory However, it doesn't match the inventory valuetion report.

The Inventory Valuation report is a snapshot a the end of the month. If you would like to compare through the Inventory Activity Detail report, you would have to take From period as the first period you started booking. What do want to achieve? You also have the option of ‘Inventory Balance’ (which is a search).

To be able to see all the transactions that will equal to the inventory valuation report as of a specific date in a saved search