Incorrect hover label for missing last value with hovermode x-unified and tickson=boundaries #7152

In this codepen the hover label for the last x axis value is incorrect. It displays "AC" in the hover, even though the correct value should be "Other".

The problem seems to be related to the missing last value (null) in the line trace. If that value is present, the hover labels work correctly.

The problem disappears when changing the width of the chart or reducing the number of data points.