What If... Captain Carter Were the First Avenger? - S1-E1
Other mistake: The premise of the first episode is flawed; "a single choice" should make the difference, the choice being identified as Ms. Carter not leaving the room to get in the observation booth. But in the normal timeline the booth is exactly where all the other characters were. In this reality everyone else is downstairs, with the German spy that inexplicably sets the bomb early. If anything, it's his bizarre, suicidal choice that matters.