Not seeing IW option in the dropdown

I currently have an in person appointment for my mother in Chennai for Oct 2022 for B2 visa (which is of no use, but took it as it was the only thing available), although my mother qualifies for interview waiver (her old visa expired only April of this year) If I click on reschedule, should I see dropbox appointment slots if they become available or should I cancel my existing appointment to be able to see dropbox slots? Currently, I don’t see “IW” at all in the dropdown, just “VAC” (Visa Application Center) and of course there are no slots being released for VAC, just the dropbox IW appointments. So wondering what is happening here. Shouldn’t I see IW in the dropdown if you qualify for waiver?? My mother’s visa expired in April of 2021, and she is applying for the same visa category in the same consulate. Is it because she already has an existing OFC and CA appointments for Oct 2022?