Jakub,
Syncing crosshair across multiple charts is not available as an inbuild feature, as of now. However, by simulating mouse-events across charts you can achieve it as shown in this JSFiddle.
If you are still facing issue, kindly create JSFiddle reproducing the issue you are facing and share it with us so that we can look into the code / options being used, understand the scenario better and help you resolve.
—
Vishwas R
Team CanvasJS
