Like Travis Hall said, such clue targets two cards. There are many good reasons to do that.
The more common and useful is to “pre”save a card (ex: at the begining of the game you clue a 1 and a 5 with only one color clue).
You will do that all the time, so it’s totally rational to considerate the same behavior even with a M card.
If you play with 375+ elo, all players will play the left most, cause it’s the convention on BGA.
Anyway, to avoid this rare situation when you want the right card to be played, you can:
- clue number before the chop
- clue it as a finesse (ex: if the Y card is a Y3, you clue Y and then make play the Y2 by the previous player, then no more hesitation).
- wait the card to be on chop and clue it like a save. You will finesse it later in due time.
- make the Y card’s owner do other thing than discard until that the M card is playable (if the M card is the 5, you may have anticipated it and clue it as 5 before, instead of G)