QML hangs in debug mode run (ctrl+R) *only*

[SeDi]

Hi,
in a rather big project I have a condition where one Dialog hangs when I quickly click on a SpinBox multiple (like 10-15) times in a row.

This happens in debug mode run (ctrl+R) only - neither while really debugging (F5) nor in release mode does this ever happen.
The code of the spinbox is quite simple, it does even hang, when I comment out the whole onValueChanged block:

SpinBox {
            id: percentSpinBox
            property bool disableSpinBox: false
            editable: true
            height: parent.height
            width: implicitWidth
            from: -100
            to: 200
            value: IncEditInterface ? IncEditInterface.percentValue : 0
            onValueChanged: {

                console.debug("entering spinBox' onValueChanged with "+value)
                console.debug("disableCombo is "+symbolCombo.disableCombo+", disableSpinBox is "+disableSpinBox)
                if (!disableSpinBox && IncEditInterface) {
                    console.debug("spinBox starts to work")
                    disableSpinBox = true
                    symbolCombo.disableCombo = true
                    IncEditInterface.percentChanged(value);
                    symbolCombo.disableCombo = false
                    disableSpinBox = false
                }
                console.debug("leaving spinBox' onValueChange with "+value)
            }
        }

Normally, there is a "half recovery" after a while, meaning that I can see the program reacting again in my Application output, but the UI stays unresponsive, sometimes I even have a weirdly blurred output like on the pic attached, that normalizes when I resize the dialog - but not to the current value, just to the value before the hanging.

I have neither any idea of the root cause, nor do I see a possibility to get to its heart, because it doesn't happen when in step-by-step debugging.

Any hints on how or where to look would be highly appreciated.
[sorry for the typo here, gotta be "unnecessary"]

[Diracsbracket]

@SeDi
What kind of object is IncEditInterface?

Does IncEditInterface.percentChanged(value) result in IncEditInterface.percentValue to change?

Do you somehow also set the Spinbox's value inside IncEditInterface ?

Have you tried with another Qt version?

[SeDi]

Thank you, Diracsbracket! I have tried out the hints in your questions, but finally the solution came from a totally unexpected ANGLE (sorry for the pun). With QtCreator 4.7.0 the default for QT_OPENGL has been changed from "desktop" to "angle" - I just had to change this back and everything is fine again (several other problems were solved as well by this…).

For posterity: go to Projects | RunSettings | Run Environment and set QT_OPENGL to "desktop" (without "").