Currently, if Grid's Row/Col Definitions are created via a Grid's Adorners, the first Row/Col value input always seems to work as expected. However, if a second Row/Col definition is input directly after changing the value of the first one, a new value cannot be input.

This issue seems to be reproduced most easily if creating Grid Row/Col definitions within a Template - however, it sometimes still occurs when within a Grid at a Page level.

See attached video.

Repro Steps:

1) Create a Project with a MainPage.xaml
2) Introduce a Button Element to the Page.
3) Right-Click on the Button, and from its Templates sub-menu, select 'Create', and store it in any desired location.
This will enter the Button Template in the Template Dummy Editor.
4) Convert the Root Border into a Grid, and select the new Grid.

5) Hover over the left or top edge of the Grid, and click on the blue highlight to create a second Row or Column.

6) Change the value of one of the Rows/Columns by clicking on its Value adorner, and input a new value.

7) Immediately click within the other Row/Column, and input a new Value for it within its Value adorner.
Observe how the input field accepts no input.
Expected Results: Grid Row/Column adorners are able to accept values input into them at any time.