Not a locksmith but I recently a S&G safe lock adventure. If you can feel the second "tumbler" drop into place the lock is broken. The arm that drops into the dials doesn't contact dials untill you turn dial to the right the final time.
On the final right turn does it free spin or grab and stop?
If it free spins the combination probably wasn't entered correctly. Try 1 digit higher and lower then the combination to see if it's just off a little.
If it grabs and stops on the last right the combo is doing its part and maybe the fail safe has somehow been engaged.