Just found out that mobile versions of a WordPress theme aren’t automatically turned on. And they have to be turned on from Dashboard > Appearance > Mobile.
Does this apply to themes like Divi too? I’ll have to check and update this post.
Okay, so I tested the 2015 theme and it seems like much of the functionality remains unaffected whether the mobile theme option is selected or not. So, I don’t know exactly what that option does or doesn’t do.