Has anyone finished around the world and gotten 96 compasses? I completed the event and found only 90
Yes, I got all 96.
You can use the link below to access the screen maps for Around the World locations. They show the empty frames where the compasses where found. You can compare the screen maps to your game.
You can find the counts of the Compasses in each location on this Wiki page:
The conpasses count as tiles so if you have any mines you didn't clear, then check those. If you cleared everything (including the Challenges) but only have 90, is it possible you bought food energy, the Piece of Compass Cake, with 6 of them?