That makes sense. When I was making my ADRs I had a hard time getting a confirmation screen, so I kept going back and researching. Then, I got on here, and found out that those ADRs still could have gone through, but never sent me an e-mail.
I'm planning to call and make sure I don't have a bunch of duplicates, because its entirely possible.
I, too, was unable to get any kind of confirmation for my online ADRs. I'm on a Mac with an older operating system, and the Disney website just kept sort of timing out every time I'd try to book lunch at both Biergarten and The Plaza. I tried probably three or four times before I gave up and called Disney Dining.
I was assured by the CM that unless I receive an email confirmation, I do not have an ADR and, according to her screen(s), I did not have any reservations. She went ahead and booked our party.
I called back in about a month to add another to our ressies. I called back again in another two or three weeks to add Boma and Brown Derby to our itinerary.
We show up to these places, and, wouldn't you know the CM at the check in podium tells us we have four reservations for our alloted time. It only happened at those places I tried to book online initially.
Not one CM over the phone all the times I called could see I had had some kind of trouble with the online system and had basically quadruple-booked.
Sorry to go a bit off topic, but at least as of a few weeks ago, there were major problems with ADRs booked online.
FWIW, I asked the lady at the Plaza if this would have prevented three other people from booking, and she emphatically stated it would not have; that they're still working out the glitches in the system, and this is happening to a lot of people. They were actually pretty empty at the Plaza for lunch (during Free Dining, no less) and the couple in front of us was a walk-up who were seated without an ADR.
I'm sticking with the phone for my ADRs.