When you "went back", were you in Finder or Time Machine and specifically, what file(s) were you looking at that were blank? Contacts' "cards" are records in an SQLite database and cannot be viewed without using the database system. Time Machine doesn't have the ability to recover individual database records; you can only recover at the file/database level. ☹ï¸
If we knew what it was we were doing, it wouldn't be called research, would it?
