It’s hard to know for certain why they didn’t bloom again, but heat in the early part of the season may cause blooms to fail. Or poor growing conditions in the prior year—despite appearances. If you cut off the foliage after the bloom last year you removed the bulb’s survival strategy; the foliage makes energy for the next year. It’s too late to try again for this spring, but don’t give up entirely. Plant some bulbs this spring that will bloom later this year. See for details: /content/growing-guide-spring-planted-bulbs
It’s hard to know for certain why they didn’t bloom again, but heat in the early part of the season may cause blooms to fail. Or poor growing conditions in the prior year—despite appearances. If you cut off the foliage after the bloom last year you removed the bulb’s survival strategy; the foliage makes energy for the next year. It’s too late to try again for this spring, but don’t give up entirely. Plant some bulbs this spring that will bloom later this year. See for details: /content/growing-guide-spring-planted-bulbs