I find that Gouramis like to have their own hidey holes, especially love to have overhead plant cover for some reason. When I trim back one of my "wild" plants, uncovering the top of my aquarium, my powder blue seems very unhappy. Once the plant grows back and starts covering the top of the tank again, you will find him swimming happily underneath the coverage.
They seem happiest when they knnw they have a little "home" to swim to if they want it.