Async loader and QQC2: Object destroyed during incubation

STEPS TO REPRODUCE:
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1. Download and extract attach project.
2. Build and run this project in Qt 5.12.7, any compiler proposed in the "Environment" field.
3. You will see 3 pages with vertical navigation on the left. Initially, you are on page 1. Switch to page 2 by clicking on the button on the left bar "Page 2".
4. You see “Hello Qt Community”, then switch back to page 1.
5. Observe of content page 1.

EXPECTED RESULT:

5. When we go back to page 1, we see the content of page 1. (Empty red background, transparency 0.3)
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ACTUAL RESULT:

5. When we go back to page 1, we see the undestructed content of page 2 and the distorted background color.
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REPRODUCIBILITY (%):

100%
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