Currently, if changes to Linear Gradient Stops are made within a Template, they cannot be undone and redone via the Undo/Redo Stack.

This appears to happen exclusively within a Template, and does not impact Gradient Stops created on an Element directly within a Page.

See attached video.

Repro Steps:

1) Create a Studio Project Featuring a MainPage.xaml

2) Introduce a ProgressBar Element to the root Grid of the Page, give it a 'Value' value to be able to see its fill.

3) Create a Template for it the ProgressBar, named and saved as desired.
This will open the Template in the Template Dummy Editor.

4) Select the PART_Indicator Border Element in the Navigator, and change its 'Background' Property to a Linear Gradient.

5) Change the colour of each of the two Gradient Stops to any two new colours.

6) Close the Brush Picker panel, and multiple times, press Ctrl+Z or undo via the HambugerMenu's 'Edit' section.

Observe how each of the individual colour stop changes within the Linear Gradient are not sequentially undone.

7) Once a multiple of 'undo' actions have been performed, perform the opposite action and 'redo' a multitude of changes.

Observe how the colour changes made in Step 5) are unrecoverable.

Expected Results: Gradient Stop changes are included as part of the undo/redo stack.