The Local checkout server behavior is on this page 6 times. It looks like you have run the checkout wizard multiple times.
The checkout wizard is not re-entrant, if you run it again after crating the checkout pages, it will just add more instances of the server behaviors, this is likely the cause of the issue. In live mode, it is processing the first time successfully, the second and other times, it is seeing a duplicate transaction occur, so is failing.
I would delete the existing checkout pages, then run the checkout wizard once again to create clean checkout pages with only one instance of the server behaviors on it.