Ambient occlusion appears to be broken in the current open beta (not 3rd person). Attached is images showing ambient occlusion maxed out on live build versus on open beta build. The open beta build does not have any ambient occlusion on the avatar at all while the live version is obvious that it does have it. It primarily affects the MSVO version of ambient occlusion which is usually the most commonly used as it functions better.

Ambient occlusion is great for pictures, so having it broken would limit many users who would rely on it. It also would affect how worlds that use it look as well.

A few worlds that have ambient occlusion in the post processing settings or is on by default:

Urban Refuge

Cozy Cottage

(Blank)