To achieve this, I suggest using the tickPositioner
function on the axis. You can make it to always return just one tick positioned at the center of the axis range.
API reference: https://api.highcharts.com/highcharts/xAxis.tickPositioner
Demo: https://jsfiddle.net/BlackLabel/63g80emu/
tickPositioner: function () {
const axis = this;
const range = axis.max - axis.min;
const center = axis.min + range / 2;
return [center];
},