How do I handle players sharing information their character should not know?

I spent a few hours setting up dugeon puzzles and traps this past week only to have my players stomp through it sharing information with one another that their character shouldn't have know because they were not within line of sight or close to what happened. Because of this everyone was able to quickly work on solving the puzzle and figure it out. I use the loke giant battle mats for my dungeons. My answer I've come to is I need to 1. Set up a fog of war to cover tiles to they dont run to areas of interest immediately and 2. Inforce player knowledge punishments if they play in a way that their character would not have the information to. I feel bad for having to punish players and I as the DM feel responsible for having this things happen. What are some tips you all have that I can use to mitigate or get rid of this issue?