I know it was during 2020 when they were extending dates and enrollment centers were closed, so in reading some of the posts above I wonder if I just misread the dates and my application did expire... given hard few appointments are available now, maybe this was just going to happen anyways! My wife had gone through the conditional approval just after me though (expire August 2020, grace period to August 2022) and hers says she has til Jan 2023 to schedule her interview.