Currently, if you click-and-drag a Slider element within the Studio UI, and you drag it outside of the bounds of the Application window, it can result in the cursor continuing to be captured by the Slider's Thumb/Dragger.

This can result in a the Slider's Thumb being moved left and left with the mouse movement, without it being actively clicked-and-held.

Repro Steps:
I have been unable to repro this issue after we noted it in our Workshop meeting, within Studio Unreal in particular.

However, the situation was as follows:
With multiple monitors set up, and Studio Unreal occupying one monitor:
1) Select an Element, exposing its Properties Panel.
2) Identify a Property (such as 'Opacity')
3) Click-and-Drag the Opacity Slider Thumb, until the cursor physically exits the Application window, onto a second monitor.
4) Release the mouse-click whilst still outside of the application window, then move the cursor back to Studio.

Observe how the Slider is still being captured even without the Mouse still being pressed.

Expected Results: Releasing a Slider's Thumb, liberates it from capture, regardless of whether the release is performed physically inside, or outside of the Application window.