StackLabels aren't correctly positioned with multiple yAxis

[Izothep]

Expected behaviour

StackLabels should be placed directly above series points

Actual behaviour

StackLabels are placed according to the last yAxis position. When multiple yAxis have different position, stackLabels are outside specific series plotArea.

Image:

Live demo with steps to reproduce

http://jsfiddle.net/BlackLabel/0s6h8zh7/1/

Product version

Highcharts v6.0.5