Look at the dorsal fin.
In many Gouramis the male has a longer dorsal fin, and somewhat pointed to sharply pointed. The female has a more rounded dorsal fin.
You can google some images and see the difference.
You will see different colors of fish. The original Honey Gourami males are the ones with the black throat, and yellow dorsal fin. "Throat" can be almost all the head and way down to the lower fin. But if he is faded out you can still see where the black would be, it is sort of grey, not orange. Look at the dorsal fin. It has a point, but is not long and drawn out like some other species.
Most of the pictures of the females do not show the horizontal stripe, but find some and look at that dorsal fin. Not a lot of difference from the male, but a bit shorter. Enough that if they are in the same tank you could tell.
Gouramis are territorial, and can get aggressive toward each other. Even a male and female may not get along.
Honey Gouramis are usually more easy going than some other species, but you might have some that are more pushy than average, or too small a tank for them to get away far enough from each other.
You might also have 2 males. They will not get along.
There are several color varieties. I think they are hybrids with another species. Some are more red, not really orange, and some are pale, like the female Honey Gourami. Most of these do not show the horizontal stripe, or the intense color of the male. Most of these do not have a black area.
Yes, that stripe can come and go. The fish has control over the coloring.