MSAA dones't work?

Hi, All

I am developing VR project on PS4 platform and found a problem when I turn on Forward shading and MSAA Anti-Aliasing Method in the project settings, then run on the PS4VR, and the MSAA don’t work at all !

even i change the r.MSAACount and r.MSAA.CompositingSampleCount to the maxium and no response

so I turn r.MSAACount to 0 become Temporal AA that was OK

so is the engine problem or is there other way to active MSAA on PSVR?