I unrolled my 2012 iMac on the beta program and installed the public beta 7. As soon I updated my iMac I've a lot of graphical glitches and freezing after few minutes of usage. I noticed anyway something strange. My build number is 16A312a instead of 16A313a. This is very strange, I'm trying to update on App store, but I don't see any update to 16A313a. Am I the only one with this problem?