A widget set in the Grid Panel reverts back to it's default size and position when compiled

A widget set to a specific row and column within a Grid Panel, that has been assigned multiple rows and columns, and then spanned across other rows and columns reverts to it's default position and span when compiled.

Repro Rate: 3/3

Tested this in //UE4/Release-4.27 @ CL#18319896 and the issue did not occur there, it is a regression.

If this is intended behaviour, there needs to be a warning or something similar to inform the user before they compile.

1. Create a new Blank blueprint project
2. Right-Click the content browser and create a new Widget Blueprint. (User Interface/Blueprint Widget)
   • Select the Root Widget as User Widget
3. Open the Widget Blueprint
4. Utilizing the Palette, drag and place a Grid Panel
5. In the details panel of the Grid Panel
   • Fill Rules > Add several array elements to the Column and Row Fill setting each added to 1.0
   • Render Transform > Transform > Set Scale to 5x5
6. From the Palette, drag and drop an Image into the frist Row and second to last Column of the Grid Panel
7. In the details panel of the Image widget
   • Slot (Grid slot) > Set the Row Span to 3 and Column Span to 2
   • Observe the slot
   • The Slot does not fill up the last column as per it's span.
8. Compile the Widget

Results: The image widget reverts back to it's default size and position when compiled.
Expected: The image retains the user assigned padding.