I would like to make a reservation for the London Paddington to Penzance route, as described here: https://www.seat61.com/interrail-and-eurail-reservations.htm#how-to-make-reservations-in-britain. When I select ‘Make a reservation’, the mentioned pop-up with ‘Next’ appears for a fraction of a second, immediately followed by an error message. I have tested this on several browsers and also on mobile devices, and the result is the same everywhere. My pass has not yet been activated, but I don't think that should be the cause of the problem. How can I make my reservation? Any help would be appreciated.
A few screenshots from a short screen video. The whole thing happens at top speed, with no chance of catching the Next button.
