QSlider takes unnecessary steps

I try to use QSlider, but if someone clicks on the X position where he wants to place the slider, the slider always sets the maximum or minimum value first, and then the X value. Thus, this is an unreasonable step between each other. How can I avoid this step?

I implemented a slider using QTDesigner. The code for the remaining installation is as follows:

_ui->horizontalSlider->setRange(1, aMaximalValue);
_ui->horizontalSlider->setValue(theCurrentValue);
connect(_ui->horizontalSlider, SIGNAL(valueChanged(int)), this, SLOT(onValueOfSliderChanged(int)));