Thanks for your first post on the Community Forum and welcome! I'm sorry to hear that you are having a problem viewing your Sky Sports via TV Anywhere in full screen using Safari. Apologies as well for the delay in getting back to you on this.
The main issue that comes to mind is that Silverlight may need to be uninstalled and reinstalled. I've also come across suggestions on this issue to go into the TV Guide and choose your programme from here and it will allow you access to control the screen size.
Give these a try and let me know how you get on.
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