REG: Opacity is not always applied to children

Steps to reproduce:
1. Start attached main.qml

What did I expect:
Both the red and blue rectangle should have the same visual opacity

What I observed:
Only the red rectangle got the visual opacity as specified

This is not necessary tied to the timer (I observed this originally as a result of a network request).

You can also click on the red rectangle. It will then toggle the opacity from 0.1 to 0.9. However, in this case it seems that the red rectangle is painted on top of the blue one.