Mine seems to be working OK here today (though I'm using Safari 13.0 with the public beta version of Catalina here).
Do make sure you disable any ad-blockers as well and they can cause issues. I use Ghostly Lite here and I have to make sure I disable that before making any purchases via affiliate websites such Shops Away, Virgin Money Back or Quidco etc. Even just whitelisting the sites doesn't always work.
The VS website in general is useless though when trying to use Safari. It's clearly not tested using Safari on a Mac!! It often falls over when trying to book flights online.
Safari on iPad isn't much better either
