Hang on, when I buy a ticket with say Capitaine Train I cannot change the seats online? Neither on Eurostar, nor on Capitaine Train? I was going to buy all my future Eurostar tickets on Capitaine Train's mobile app because the Eurostar mobile app is rubbish (need to enter pax details every time anew), and the Capitaine Train app also allows for changing trains, and I have less access to my PC with the full website. But often I also want to just change seat assignment, but now I am learning that the Eurostar system will not even recognize the ticket bought over that other platform? Rubbish indeed if true.