The Electoral College is elected on the first Tuesday after the first Monday in November (United States presidential election - Wikipedia).
The President is then chosen by the Electoral College no sooner than January 6 (Counting electoral votes in Congress).
Generally the members of a College publicly commit to a specific candidate in advance, so in practice the November election immediately determines the President-elect.
When was the last time, if ever, that the College ended up choosing someone in January other than the "winner" recognized immediately following the election in November?
NOTE: this question is related to Do any other countries take as long as the US to transfer government power following an election? - Politics Stack Exchange. Some answers are saying that the question isn't valid because the President isn't really known until January 6 at the latest. In theory that's true, but in cases where the November result is decisive, is it true in practice?
UPDATE: Based on the comments, what I'm asking appears to be unclear still.
It is not asking about situations where there is brief confusion at the time of the election (1948) about who won.
It is not asking about where some state results for the electoral college are contested.
In the typical case, one candidate concedes defeat and one accepts victory. In 2016 for instance, the vote was close, but during the night following the election:
at 2:50 a.m. Trump gave his victory speech. Later that day, Clinton asked her supporters to accept the result and hoped that Trump would be "a successful president for all Americans" — Wikipedia
Yes, it wouldn't be official until January, but for all practical purposes, Trump was considered the winner.
What I'm asking about is situations where everyone knows who "won", but some members of the EC later changed their commitment and as a result reversed the apparent victory.