some years ago I had Raccoon problems. They kept getting the bait. I set up a video camera. They worked in pairs (there were 6 of them). One on each side of the trap they worked together to untie the bait. setting off the trap in the process. I ended up using a piece of fried chicken and used wire to tie it to the trip paddle. And as others have said blocked access to the sides of the trap. forcing them to go inside.
At one point they even tried to carry the trap off with the bait. That made good video, one on each side standing up and carrying the trap like little old men.
Raccoons are very smart and very nimble with theirs "hands", good climbers, fit thru small holes, can tear open chicken wire, untie things and open most latches.
Good Luck.