For some reason Im not able to add a picture to this but whats going on is a unity loading thing but this is a known bug and happened to a few other games i have tried, Im not sure why it happens though, as well as the card didn't respawn and just fell into the water right beside the heart card, I didnt play much after that though do to the mouse thing making it to hard to play so it could have respawned without me realizing it.
There are two Diamond cards in the pile, which intentionally don't respawn.
So just to be clear - you got up to the roof, you took the Ace of Hearts down to the island, then the Ace of Hearts card fell into the water near where the other deck of cards was, and the Ace of Hearts card didn't respawn on the roof?
No, it seems like I must have just saw the red diamonds and it looked to be like hearts, like I said, I wasnt able to play much after that do to not being able to play the game easily due to the difficulty of being able to look around and play the game, I am so sorry for the inconvenience, if I would have known I wouldnt have made the comment in the first place, I am honestly sorry if this took time out of your day.
P.S. - if you couldnt tell, im really sorry