Shadow option disappeared from 3d & materials section of illustrator

Hi, I’m facing a really strange issue with Adobe Illustrator. The shadow option is missing from the lighting section under the 3D and Materials effect. It was working fine one day, but it suddenly disappeared and hasn’t shown up since.

I’ve tried several solutions, but nothing seems to work. Previously, I was at least able to copy the same 3D appearance from the Appearance panel in Illustrator, but now even that isn’t working.

Can someone help me out? Thanks!