UE 4.15.0 preview 3 hair shader no AO ?

Hi , I updated to 4.15 preview 3 today and found out that the hair shader no longer has any AO , is this a new feature that I need to turn it on somewhere or just a bug ?
I open the character render demo level and same thing happen to the demo hair shader in that level

Hi phungdinhdung,

Thank you for submitting this post. I have reproduced this issue and logged a report for it here: Unreal Engine Issues and Bug Tracker (UE-41606)

You can track the report’s status as the issue is reviewed by our development staff. Please be aware that this issue may not be prioritized or fixed soon.

Cheers,

thank you very much ! appreciated it :wink: !