@nelly25,
The gap between the y-axis title and labels is caused by the stripLines with labelPlacement: "outside"
and a transparent label reserving space in the problematic dataset (y-values ~124–233), as the stripline’s value (150) is within the axis range, affecting the layout. In the commented dataset (y-values ~43–63), the stripline’s value is outside the axis range, making it invisible and eliminating the gap. You can remove stripLines from axisY or set labelPlacement: "inside"
to fix this issue.
—
Vishwas R
Team CanvasJS