Significantly Delayed Flight not showing

(Total newbie here. This question may very well be previously discussed and have a very obvious answer, I just couldn’t find it in the discussion forum.)

In late December I was on a long-haul international flight that was delayed by 20+ hours due to mechanical issues. (Eva Air, BR35, YYZ>TPE, Dec 28 2017, scheduled to depart at 0045, actually departed after 2200) The flight was NOT cancelled, just delayed by almost a day (thus depart around the same time as the same flight next day)

When I check its flight history, that flight/day is conveniently missing. Is it standard protocol to not post a flight that is significantly delayed? Or did the airline withheld the data to protect its delay average?

Many things may have happened, but none of it was intentional to hide a delayed flight or protect delay average. It may have flown under a slightly different flight number that was not provided to you.