Eligible for interview waiver but showing vac appointments!

I am eligible for the interview waiver program for my h4 visa which has been expired last year. When trying to book the slot, it is showing vac appointments for me instead of iw. Any inputs appreciated. Thanks so much!

The dropbox eligibility was extended from last 12 months to 48 month only till 31st December 2021. If your appointment date is somewhere next year, the system may be falling back to 12 months calculation and showing that you are not eligible for interview waiver.