Currently, it appears as if there are two different interpretations rendered on Stage, in both cases with the same "Path Trim" Property set at 100%.

It appears as though when clicking-and-dragging the slider, the value is able to be dragged to 100% (showing expected visual result on-Stage), but also to a "100+" where the Path completely dissapears on-Stage.

See attached video.

Repro Steps:

1) Create a Project containing a MainPage.xaml
2) Introduce a 512x512 Rectangle Element to the Stage, remove its Fill, and set its Stroke colour to something nice and visible, and set its Thickness to 8px.
3) Identify the Rectangle's Trim Start and Path Trim End Properties.
4) Set the Trim Start and the Trim End Property each to 0%.

5) Click-and-Drag the Trim Start Property Slider carefully to the right - very carefully bring the slider to 100%, trying to release as closed to the 99% mark as possible.
Observe how if achieved, the Path displays.

6) Click-andDrag the Trim Start Property Slider all the way back to 0%, then bring it to 100%, dragging the mouse as far right across the screen as possible.
Observe how the Path on-Stage disappears.

Expected Result: A "100%" Path Trim Start value always displays the same result on-Stage.