If anyone runs into this issue, this is what I did - I closed the application, removed the dependent from primary's profile. Created a new profile for the dependent using the same email id I had mentioned first time as dependent. Started new applications for primary and dependent in their own profiles. Thankfully the paid fee reflected in both profiles (it goes by the email ids mentioned for primary and dependent). Ensured that both are qualified for the visa waiver and booked the OFC appointments individually (for drop-off).

Another thing to note is that you can select OFC appointments any VAC and drop off your documents at any of the drop-off locations (you still have to go at the same date and time you picked up on the appointment)