Hi,
I've encountered an issue with the AvailableAmount tag. It works well when you've added the product to the Cart, reflecting Stock - AmountAdded.
However, after you order the product, Stock decreases by the number of items bought, but AvailableAmount decreases by twice the number of items bought.
After purchasing 5 items, Available Amount decreases by 10.
See the video below where I output the Stock and Available Amount tags and then go through the checkout process: