[Solved]-Highcharts Gantt - how to force data labels to always be above milestones?-Highcharts

you can position data labels above the markers by using y property:

  series: [{
      ...,
      milestone: true,
      datalabels: {
        ...,
        y: -10
      }
    }, ...]

live demo: https://jsfiddle.net/blacklabel/yv641op0/

api reference: https://api.highcharts.com/gantt/series.gantt.datalabels.y