When the player at index 0 sets its user focus it will cause other players to lose input. This does not occur when setting the user focus of players with an index higher than 0.
Result: Player 2 will have lost input control
Expected: The input for player two would not be affect by setting the user focus of player 1
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-70794 in the post.