Male Gynecomastia

As I gain weight, I notice my chest sagging even though I am male. I wonder if this is simply due to gaining weight or if it could be gynecomastia.

First, I need to lose some weight, and then I can look at the shape, right?

I heard that it could be due to glandular tissue. I'm also a bit worried whether such changes can occur artificially, not just because of fat.

I didn't used to do this before, but now I have to take off my outerwear when I go outside, and it's subtly stressful.