Issue
A desktop mouse can drag the interface, while touch input only scrolls or selects nearby controls.
Cause
The UI relies on mouse events, a scrolling parent captures the gesture, or another transparent object sits above the handle.
Fix
Use UIDragDetector-supported input rather than MouseButton events. Inspect ZIndex and Active behavior, then isolate the handle from scrolling content. Make the touch target large enough without covering adjacent buttons.
Verify
Use Studio touch emulation and a physical phone; test one finger, quick taps, and dragging inside a scrolling frame.
Official Roblox UIDragDetector announcement
#1
Original Heliotrope guidance with authoritative Roblox sources.