Gourami do tend to hang around the surface, males build their bubble nests at the surface, and they feed from the surface. They like to hide away in plant matter, especially when there's a lot of activity in the tank which you'll have with all those male livebearers. Not surprised he picked that spot where the fake plants are tallest to hide away. He'd probably benefit from some real plant matter floating there he can make his own hiding spots, like a big bunch of elodea, water sprite, guppy grass, something like that.
I can't see any signs of illness or disease on the fish myself, think you might have a male/female ratio problem though with the livebearers, think you have a couple of female mollies, but more males. That could well be a problem with the males harassing and chasing the females too much. That adds stress and eshaustion, can eventually kill a female.
Sounds like it's a new tank? And probably a cycling/over stocking too fast problem. Large water changes for now, using declorinator and temperature matching the new water to the tank temperature, then we can talk you through how to do a fish in cycle, and remedy the stocking problems