The current row indicator visual (the right pointing arrow) gets hidden if you enter edit mode of a cell (which shows the cell edit indicator) and then press Esc two times. The first time cancel the cell editing and the second time cancels the row editing. 

This reproduces in the VisualStudio2013 theme.

To work this around, extract the ControlTemplate of GridViewRow for the VisualStudio2013 theme and add the following MultiTrigger at the bottom of the template (last in the ControlTemplate.Triggers collection).

<MultiTrigger>
	<MultiTrigger.Conditions>
		<Condition Property="IsValid" Value="True"/>
		<Condition Property="IsCurrent" Value="True"/>
		<Condition Property="IsInEditMode" Value="False"/>
	</MultiTrigger.Conditions>
	<Setter TargetName="NavigatorIndicator" Property="Visibility" Value="Visible"/>
</MultiTrigger>