Did this for the first time last night :(
I should have known as it did not give me the option to fill in address from my saved address as I usually do..
In my case I kept the tansexe window open in one tab, opened a new tab and signed into biggie, then when I pressed continue on the order made screen. it gave me the option to add order to my account. It all appeared in my orders as normal after that.
Hope that helps someone.