UE4 Baked AO doesn't work.

For some reason Ambient Occlusion simply doesn't work in my project. I'm talking about the one in World Settings.

Here are the settings:

After several unsuccessful attempts at having AO after baking the lighting, I cranked Exponent to 4 just to see if there's ANY AO at all and maybe it's just barely visible. But no.

As you can see, there's literally no AO whatsoever:

I'm really confused about what's going on. Because I specifically remember using this feature several times in the past and everything was fine. And yeah, I checked project settings and AO is enabled.