`pointFormat` wrong timezone displayed when used with `#if` or `#unless`

[jedrzejruta]

Expected behaviour

The tooltip date should be displayed according to given timezone.

Actual behaviour

The tooltip date is displayed according to system timezone, disregarding given timezone.

Live demo with steps to reproduce

https://jsfiddle.net/BlackLabel/Lzayofu7/
Remove the #if statement, and the date will be displayed correctly.

Product version

Regression introduced in Highcharts v11.1.0

[hubertkozik]

This issue is reproducible also for Highcharts with line series: https://jsfiddle.net/BlackLabel/4z5qb09L/ not only Gantt.