Form 2106 flags 'Date acquired' as invalid. It can't be after 'Date placed in service' (9/3/2016), but I moved into my office home on 12/21/2020. How can I fix this?

The questions about placed in service and date acquired apply to the home office asset, not your tenure as clergy. So, if you purchased the home in 2016 (date acquired), you need a date after that for placed in service (2020). You can enter the same date for both if you moved into your home office on the date you purchased the home.