After viewing various web sites with this build in Safari after a short time when I begin opening new tabs 'multi-lined' graphics begin to appear in any new blank Tab Window. New tabs are suppose to open blank when set that way. But now after a short while of use any Tab that is open has these multi-lined grey scale graphics until a quit and reopen again. It's as if the brackground of a previous web site that has been previously viewed is hanging and elements of it are being moved into a new blank tab. Have also submitted a Feedback Assistant report with an image. This has happened twice since installation of Beta 11.
Update. As example - if I go to BBC news and then open new blank tabs the black and red banner with no BBC content duplicates itself into each new blank Tab.