Fix marker monitor overlayer flickers on hover

src/monitor/view/kdenliveclipmonitor.qml

@@ -525,7 +525,7 @@ Item {
             height: childrenRect.height
             color: Qt.rgba(activePalette.highlight.r, activePalette.highlight.g, activePalette.highlight.b, 0.7)
             radius: 4
-            opacity: (dragAudioArea.containsMouse || dragVideoArea.containsMouse  || thumbMouseArea.containsMouse || (barOverArea.containsMouse && (barOverArea.mouseY >= (parent.height - inPoint.height - height - 2 - (audioThumb.height + root.zoomOffset) - root.baseUnit)))) ? 1 : 0
+            opacity: (dragAudioArea.containsMouse || dragVideoArea.containsMouse  || thumbMouseArea.containsMouse || marker.hovered || (barOverArea.containsMouse && (barOverArea.mouseY >= (parent.height - inPoint.height - height - 2 - (audioThumb.height + root.zoomOffset) - root.baseUnit)))) ? 1 : 0
             visible: controller.clipHasAV
             onOpacityChanged: {
                 if (opacity == 1) {