There seem to be two ways this shows depending on the starting conditions.

A) scaling up is not working:

• set scale to 100%
• start attached application
• change scale to 200%
  -> red and blue rectangles stay at the same pixel size as they were

However the window is expanded. This causes green region (clear color) to be showing outside of it. Clicking in the green region does nothing even though there should be a MouseArea covering the whole contentItem.

Clicking the red or blue region however work as expected.

B) scaling down is not causing a repaint

• set scale to 200%
• start attached application
• change scale to 100%

-> The red region now covers the whole window.

Clicking the window now causes it to repaint and now it is showing up properly.