Issue
The panel jumps when dragging begins or follows the pointer with a visible offset.
Cause
AnchorPoint, parent scaling, and the initial grab position are not being accounted for consistently.
Fix
Use UIDragDetector rather than manually mixing absolute and scale coordinates. Keep the dragged object under one predictable parent and review its AnchorPoint. If applying constraints, constrain the final desired position rather than resetting Position during every movement callback.
Verify
Grab each corner of the panel at multiple window sizes and confirm the original grab point stays under the cursor.
Official Roblox UIDragDetector announcement
#1
Original Heliotrope guidance with authoritative Roblox sources.