Sometimes enabling the Particle Backgrounds does not display particles in the background. This might happen because widgets are covering the entire row and there is no space for particles background to show up.
For example – In a row, you have added a heading and added a spacer above and below the heading. This will occupy the entire space in the row. So particle backgrounds added to row will not display as it has heading and spacer above it.
To solve this you can remove the spacer and add padding for the row. So that particle backgrounds will display.