Don't give up hope. I booked at 2:30am for two lunches in March, and all of the times were available at that point (and I'm sure very few were online). I looked again at 5:30am (just out of curiosity), and most times were available. I have zero factual evidence, however my guess (based on what I saw at 5:30, and between 6am and now people have been unable to book) is that there are still a lot of times available, but they have taken them all down to fix the system. Keep trying, and good luck!