No ambient light from skybox source

Hi,

I can't seem to get the Skybox option in the Environment Lighting settings to work, even when using the Default-Skybox material. When using Gradient or Color it seems to be working fine, but I want to be using the skybox for the ambient lighting.

Here's a gif showing the problem:


Is there perhaps some option in Unity that needs to be enabled, or am I missing something?
I'm on Unity 2019.3.4f1 using the built-in renderer.

 

Enable this:

 

That did the trick, thank you so much!
I just assumed that the light generation was specifically for lightmaps, which I'm not using in my project, but little did I know

 

Yep, it's also used for baking the spherical harmonics light probes, including the default probe (which is based off of the skybox alone).