WebGL Preview - Gradient don't work in the browser

Shapes with a gradient fill only show up ad the stroke in the browser via WebGL streaming.

Error message from the Application Output:

[+file:///Users/brook/qt_dev/untitled68/imports/QtQuick/Studio/Components/ArcItem.qml:136:9+]: Unable to assign int to QColor

Warning: Setting a new default format with a different version or profile after the global shared context is created may cause issues with context sharing.

QSGContext::initialize: depth buffer support missing, expect rendering errors

QSGContext::initialize: stencil buffer support missing, expect rendering errors