When Covid-19 shut down production for several months in 2020, that didn’t only disrupt shows that had been in the middle of production at the time. It created a ripple effect that extended well into 2021, forcing many series to delay production for more than a year as Hollywood struggled to get back on track.
https://www.adweek.com/convergent-tv/popular-shows-that-didnt-air-new-episodes-in-2021/