Think it's because they are not deep enough. Dig them up put some growmore or chick.pellets into the soil re-bury the bulbs but deeper this time and see what happens !

You do not say when you planted them? Did you leave the leaves on for 6 weeks and feed them after flowering last year. Or are they up against a fence or wall (perhaps on a slope) where they are too dry? both can cause nonflowering also.