showCrosshair property
Show X and Y axis crosshairs (if they exist) as the chart plays.
Note that if multiple tracks that play at different times try to show the crosshairs, it can be glitchy, so it is recommended in those cases to turn this on/off for individual tracks using the showPlayMarker option.
API Docs: https://api.highcharts.com/highcharts/sonification.showCrosshair
Implementation
bool? showCrosshair;