To solve the flickering problem, we have to adjust the Depth Offset property, but
avoid making extreme adjustments. The best option is to press and hold the Shift key
to make accurate adjustments until the flickering stops.
This flickering happens because when two surfaces are on the same place, Lumion
does not know which of the two materials should be on the front and on the back.
The Depth Offset option can correct this issue, but this situation needs to be
addressed when modeling to avoid having two surfaces on the same place.