I can't remember the specific example, but it was a scenario where the source language was ambiguous but the target required more specificity. It was like "give me some bread" in one language and then when I supplied "give me a piece of bread" it told me it should have been "give me a slice of bread".

While I could see where it was coming from, this would be incredibly confusing for a beginner, who wouldn't even know to report this as a problem - they might conclude that "piece of bread" was just incorrect.