If you outsource CNC machining, you are probably seeing component prices rise. For buyers that are focussed on getting best value for money, an environment where prices are rocketing can make your job very hard indeed.
You're having difficulties with a precision component for a critical medical device. The part won't fit the assembly. Or the finish isn't right. Or the quality/consistency is hit and miss. Or any number of other issues. But your existing supplier – who perhaps has been reliable up until now – is pushing back: they did "exactly as instructed", they protest. They followed your drawings/CAD models "to the letter". So what went wrong? And how can it be fixed quickly and cost-effectively? You want a second opinion – is the issue with the supplier, the drawings or both?