Product added to cart more then qty avialable in Magent 2 backend

Hi All,
I am facing one issue like E.g any product in stock QTY: 10 and there is no backorder etc are allowed still when user clicks to add to cart button with QTY: 100 at that time it added to cart. it showing error as well but still, the product is added to cart and whenever we refresh page at that again its showing error like

{“code”:400,“result”:“The requested qty is not available”}

See attached video for more information
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