I recently had a similar problem when I created a new profile for leisure stays. As you said, after selecting the newly created profile from the dropdown list, the screen would refresh but the default profile would reappear.

If it's any consolation, I was eventually able to make it work and even made a reservation with the new profile, but unfortunately can't really tell you how I fixed it. I fiddled around for some time, including closing and reopening the browser, trying different reservations pages (PC, IC, etc.), and a few other things that I don't clearly recall. Somewhere along the line one of these must have worked. Good luck.