Hello Rlyn76,
My mom petition my 3 siblings unmarried ( 1 minor and 2 over 21 ) since yr 2019 before covid, she is green card holder. All of them were approved and all case are in NVC. However, until now we do not have visa yet. My minor brother is so far documentarily complete at NVC and still waiting for interview which is taking so long time, due to covid backlogs the processing is like a snail, we are worried as he is aging out 21 yrs old next year. My other 2 brothers that are over 21 yrs old are still waiting from NVC to tell us to submit all documents needed but so far no further action required yet, as NVC says they are waiting to become visa available.. we knew over 21yrs old will take long years processing compare to my minor siblings.. we always contact NVC but we are still waiting here no clue when is the interview coming, we hope really soon! Hope this information will help you!