So I’m working on a project, the Qt app running with Wayland and the OS is a customized Linux.

I run the Qt program with this env var QMLSCENE_DEVICE=softwarecontext, this var makes my Qt app’s CPU time reasonable and responsive, however, it makes one of my rectangle element unstable:

the rectangle is the same one, but it constantly varies width and height by 1 back and forth, no stopping.
The qml of this rectangle is:

Rectangle {
        id: xxx
        y:0
        width: 5
        height: parent.height
        visible: true
        color: "blue"
    }

I verified that no code is changing its width and height.
Simply removing QMLSCENE_DEVICE=softwarecontext and using other values like QT_QUICK_BACKEND=rhi or QT_QUICK_BACKEND=openvg would make the rectangle stable but performance is very bad, CPU time becomes unbearable, so it’s not a solution for me.

How to make the rectangle stable without compromising app performance? Thanks in advance!