Has to be a mistake. There is no way epic would censor your game like that. They don’t have any real incentive that I can see for doing so especially when they stand to make money from the game if you finish it and it sells.
It sounds to me like the foliage you want to display is not making it through the build process. Basically the graphic you chose to use for foliage is getting lost during build and the result is a different graphic being applied as well as a missing icon once picked up since the graphic for the icon is not making it through either and is not being replaced by anything else like the other part was.
My suggestion is to start looking at WHY the graphics you want to use are not making it through the build process. If you can figure it out you can probably fix this problem and prevent it from happening again down the road.