Gradient overlay does export as a single color when exporting jpeg

So here's the deal. I made image within photoshop where I have a photo, and on top of that photo I have an gradient adjustment layer @ 80% opacity. (screenshot 1). Here you can clearly see the light-to-dark orange gradient on top of the photo. When exporting this image to jpeg, I get the following result (image 2). Here you can clearly see that the entire image has absolutely no gradient. It gets completely filled with a solid color (the light orange color.) Also, the thumbnail seems to be just fine.

Saving it with the embedded color profile, or convert/assign the profile does not give any different result.

When using 'save for web' I do get the result I want, but i'm really curious what caused this, and how to prevent it.

Does anyone have a clue of what's happening here?