Thanks for the report, Modoh!
In your game, I found the situation in your turn 9. You played Harbinger (topdecking Secret Passage), then 3 Minions, the first 2 for $2, the last for discard+redraw. That left you with exactly 2 cards in your deck, which you promptly drew with the Secret Passage. Now your deck is empty, so there is only one place the card to be put back from Secret Passage can go!
You can call it top of deck or bottom of deck or something else, but after you put it back it will be the sole card in your deck. That's why there is no slider to choose the position, there is no choice to make.
The game will detect many situations where normally there is a choice to make by a player, but in a given specific situation there is no choice, then it will not ask you for the choice. That's what's happened here.