@lars_,

CanvasJS Chart just renders the data that you pass in chart-options. And in case of line charts, it draws a continuous line to connect all the non-null datapoints present in a dataseries. A gap / discontinuity in the line can be observed only when there is a null datapoint with the dataseries. You can set connectNullData to true to make it continuous by connecting line between non-null data.

If this doesn’t solve in your scenario, kindly reproduce the scenario either in JSFiddle with dummy data & share it with us (or a sample project & share over Google-Drive/Onedrive) so that we can run it locally to debug & understand it better and help you out.

—
Vishwas R
Team CanvasJS