Thank you for bringing this issue to our attention. While it's possible to use the Scrollbar's stepping feature with the Scroll Rect, this specific interaction is not well supported by the design and fixing bugs for that scenario would risk bringing unforeseen consequences.

However, we are providing you with a script that can be used as a potential workaround for this specific scenario. It does not handle any other scenario than vertical scrolling with a mouse. It is provided as a starting point and should be tested in your specific game.

The proposed solution is to detect when a scroll event is being ignored by the Scrollbar's stepping behaviour, that is when the Scroll Rect position is rounded down or up to the closest valid step, and apply the sufficient delta for the scroll to happen in the expected direction. This script is a replacement for the ScrollRect component (you can replace an existing instance by enabling the Debug mode of the Inspector and editing the Script property of the Scroll Rect and replace it with this one).

```
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

public class SteppedScrollRect : ScrollRect
{
public override void OnScroll(PointerEventData data)
{
// We're only interested in situations where we have a Vertical Scrollbar with stepping
if (verticalScrollbar == null && verticalScrollbar.numberOfSteps <= 1)
return;

// Save the current position before the scroll event is processed by the ScrollRect
float savePosition = verticalNormalizedPosition;

base.OnScroll(data);

// The scroll event has now processed the Scroll Rect, reflected in its verticalNormalizedPosition
// This value has not yet been affected by the Scrollbar's step behaviour
// Since they only sync their values during the next LateUpdate()
float diff = savePosition - verticalNormalizedPosition;

// Skip scroll events that didn't actually move the Scroll Rect at all
if (Mathf.Approximately(0.0f, diff))
return;

// This is the size between each step of the Scrollbar between 0 and 1
float stepSize = 1f / (verticalScrollbar.numberOfSteps - 1);

// A scroll delta (relative to content size) that is less than half the stepSize will result in an "ignored" scroll
// Hence we will attempt to patch it by moving to the next valid step value in the expected direction
if (Mathf.Abs(diff) < stepSize * 0.5f)
{
// Make sure to add 0.01f in order to put the value above or below the required step
float minDistanceToScroll = stepSize * 0.5f + 0.01f;

// Finally, overwrite the ScrollRect position by applying the minimumScrollDistance in the right direction
verticalNormalizedPosition = savePosition - Mathf.Sign(diff) * minDistanceToScroll;
}
}
}
```

We appreciate your input and understanding. Please let us know if you have any other concerns or issues you would like to report in the future.