I noted a possible problem see below. It seems my system was playing up and not Vegas at all. All good on this one - thanks Cornico for your checking
Original post: Sorry guys, another little bug. On slideshow (Insert>slideshow) none of the Random options for transitions work. They all default to cut edits. It works fine on 13.
It was set up OK, but I had been doing some editing that was very complex and seemed to be throwing Vegas out of sorts. A swift bit of turn it all off and on again, seems to have fixed it. I take it all back!