Ok, the issue was resolved. Here is what I did:
1)Waited a few days. Initially, the receipt number is shown, but when you click continue, it takes you to the
dropbox page. Then, a day or two later it shows a blank textbox where you can put the receipt number. If you
enter it, it says "Invalid record". Wait another day or two, and the receipt number is filled in again, and
it takes you to the schedule appointment page.
2)If you are still having issues, click on the "provide feedback". Give your name, passport number, e-mail id
and a screenshot of the page you're having issues with (I sent them the invalid record page)
3)When you get to the appointment page instead of the dropbox page, it is working.
First schedule the consular appointment. Depending on what you choose, time slots before that are available
for OFC appointment. Schedule the OFC appointment as well.
Now it's just waiting, gathering documents, and hoping for the best!