Cursor radius set via FSlateApplication::SetCursorRadius is ignored during FHittestGrid hit testing

The cursor radius configured through FSlateApplication::SetCursorRadius() is not respected during Slate hit testing. The radius value is correctly stored in FSlateApplication and passed into FHittestGrid::GetBubblePath() but the parameter is not used at all. As a result, widgets are still only detected when the cursor center overlaps them, even when the configured cursor radius overlaps the widget.

The issue was reproduced in UE 5.6, 5.7 and in UE5-Main CL 51489390.

This issue was previously registered as [Link Removed] Backlogged and discussed in: [Link Removed]

1. Open the attached repro project.

2. Run the project in PIE. The project sets a large cursor radius in C++ using: FSlateApplication::Get().SetCursorRadius(100.0f);

3. Move the cursor across the UMG widgets in the viewport.

4. Observe that widgets are only detected when the cursor center overlaps them, even when the configured cursor radius overlaps the widget.

Attaching the debugger and placing a breakpoint in FHittestGrid::GetBubblePath() you will also be able to confirm that CursorRadius is passed into FHittestGrid::GetBubblePath() but is not used.