Background is visible on low quality renders but is not visible on high quality renders.
The visibility of background image through the window/door depends on whether they are an internal fixture or an external fixture.
For example, by default, an interior door would be set as an 'internal fixture' and an exterior door would be set as an 'external fixture.'
Therefore, if you have added an interior door, by default, it will not display the background.
However, to have an interior door display the background, it needs to have 'internal fixture' disabled.
To disable a fixture as an internal fixture, follow the steps below:
1. Select the door / window you wish to see the background.
2. Go to Items Settings disable Internal Fixture
3. Once the internal fixture is disabled, you will be able to see the background.
[Note: If you do not wish to see the background on selected door/window, select them and enable internal fixture by going to Items Settings]
Changing an internal fixture to an external fixture enables light to transmit through the fixture, therefore this can affect the overall lighting of your design.