```python
def hide_values(store: dict) -> dict:
    """A store with every value starred out."""
    hidden = {}
    for key, value in store.items():
        hidden["*" * len(value)] = value
    return hidden
```

The bug was that the function used `key` (the key) as the new key in the hidden store, instead of `value` (the actual value being hidden). The fix replaces `key` with `value` so that each value is starred out once per character it contains, while the keys are preserved as-is.