QwtPolar App - Porting on Linux.

[Elisabetta]

Hello,
I am using:
1) QT 5.8
2) QWT - 6.1.2
3) qwtpolar- 1.1.1

On Windows I have no ploblems.
On Fedora 25 when the data is updated randomly colored lines appear in the title area and the graph is replicated n-times.

curve->setData(new PolarData(xData.data(), yData.data(), yData.size()));
replot();

curve->setData(new PolarData(xData.data(), yData.data(), yData.size()));
replot();

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I attach the figure with the right graph and the figure with the anomalies described above.
rightPolar.jpgwrongPolar.jpg

Can you give me some suggestions?

Thanks in advance!
Best Regards!