I have only 2 woodland champions on the board, but somehow the woodland buff is still activated. It did spawn a clone in the following combat phase.
This bug happend to me twice already. But I don't know the specific requirements for this bug to occur.
In that particular game, I had 3 woodland champions on the board: Neeko, Lb, Maokai. I put lux in for neeko, and the woodland buff was gone. Then I swapped neeko and lb a fewtimes, and suddenly the woodland buff was back.