Here is my setup: Magento 2.4.1
Stores->Configuration->Sales->Payment Methods->Braintree (sandbox)->Payment Action = "Intent Sale" (same as "Authorize and Capture")
Stores->Configuration->Catalog->Inventory->Stock Options->"Decrease Stock When Order is Placed" = Yes
Stores->Configuration->Catalog->Inventory->Product Stock Options->"Automatically Return Credit Memo Item to Stock" = No
Since all Payment Action is "Auth and Capture", the Orders are automatically Invoiced and Order Status is: "Processing"
Customer purchases a quantity of a Product Variation (a child product of the configurable product), in this case the remaining stock.
I issue a Credit Memo to Refund (either before Shipping or after Shipping, it doesn't matter), open the Invoice and click on "Credit Memo" at the top of the window, select "Return to Stock" for all line items.
However, if I manually update product Quantity and Stock Status (to In Stock) for each Simple Product Variation - the Quantity is updated BUT the Salable Quantity/Default Stock now includes the Credited Stock so that the Quantity and Salable Quantity are way out of sync.
Stock status is now all messed up - Salable Quantity / Default Stock is wrong!
It seems like neither the Inventory Reservation table or the product Stock Quantity are being updated properly when an order is returned to stock.
This seems like a serious bug...?