Currently, when you click F2 or double mouse click in order to start editing a cell (with a TextBox editor) its text gets selected. This happens because the SelectAll() method of the underlying TextBox is called. Add a property that allows to disable this behavior and to avoid selecting the text.

At this point you can get this effect by creating a custom column and overriding its PrepareCellForEdit() method as shown here: https://docs.telerik.com/devtools/wpf/knowledge-base/kb-gridview-prevent-f2-text-selection