My almost new KD-55XG went through a firmware update yesterday 18th Jan, 2021.  There have been numerous changes to the interface and YouView.  The feature I found most useful in YouView was the live tv programme restart function (green button) for BBC channels, that now seems to have disappeared.  Has anybody found it?  My slightly older KD-49XG has not had a firmware upgrade and the "watch from start" functionality is still available and operational.  It's not apparent what, if any, the benefits of the upgrade are. 

Additional note.  I live in Scotland and the YouView TV guide does not update information for any earlier programmes for any of the Scottish channels, including BBC1 Scot, STV, BBC Scotland, BBC Alba, and hence you cannot directly play the programmes from the YouView guide as you are supposed to be able to.