This site shows no AC892 flight operated on Jul 22:
https://www.flightera.net/en/flight/...20#flight_list and neither does flightradar24.
I can't find any evidence of AC778 after 26 Oct 2019. Are you sure of the flight number?
AC891 did operate 31 Jul 2020 but again, no evidence of AC891 after 23 Mar 2020.