I'm search for answer here about disappearing elements in QCustomPlot, but not find exactly what I want. When I paint two separate graphs x(t) and y(t) - zooming (in/out) is perfect, where t is time. But when I paint x(y) - I have much problems (when zoom or drag) of fully incorrect view of my graph or disappearing graph (part or full) in view-rectangle. x and y data sets are exactly the same size, both 'doubles' type. The x(y) must looks like near-concentric circles, but on some zoom stages the curve is very distorted. Tried rescaleValueAxis(bool onlyEnlarge, bool inKeyRange) - not helped. Tried play with setRange for xAxis and yAxis - not helped. Maybe I should rec some video to show how far crashing x(y) while zooming. Any help?