Bad puzzles


The vast majority of puzzles should be valid. The initial move you're looking for should be the only good move, regardless of the reply. Sometimes, a continuation is given to illustrate a particular themes (and may have been played in the original game).
If you do run across a puzzle you think is bad otherwise, validate the solution by using the Analysis option, and if there's more than one solution, or it's otherwise still a bad puzzle, you can report it on the website.
https://support.chess.com/article/1223-how-do-i-report-a-bad-puzzle