Kristin,

Thanks so much for reaching out. Sorry to hear your daffodils are not blooming.

Here’s what I can tell you about non-blooming daffodils. Generally speaking, if they aren’t blooming, it means the plants weren’t able to store enough food in their bulbs in the previous year. Daffodil foliage typically persists for 4 to 6 weeks after blooming. During this 4-to-6-week period, the daffodil foliage is manufacturing food. Much of the food is transported to the bulbs.

In order to (re)bloom, daffodils need to store adequate levels of food. Cutting off the foliage before it has died back naturally may prevent the plants from storing adequate food in the bulbs. But you note you are not cutting the foliage back prematurely... so that isn’t the issue.

My best educated guess is that one of the three issues I've noted below is the problem. Shade (not enough sun), fertilizer (too much), or (bulb) fungus.  Read on and see what you think. 

1. Plants in partial shade in May and June may not be able to store enough food in their bulbs because of insufficient sunlight. I would move the daffodils growing in partial shade when the foliage has died back and re-plant the bulbs in a garden spot that receives at least 6 hours of direct sunlight. If given good care and favorable growing conditions, weak (non-blooming) daffodils can be encouraged to flower again. You can always offer them a bit of bone meal when you replant.

2.  Too much fertilizer can be a real problem. Especially fertilizers high in nitrogen. It will encourage beautiful foliage, but few or no flowers at all. Buying and applying a fertilizer high in phosphorus can help your daffodils develop strong flowers. You can feel free to top dress with a 1-3-3 NPK fertilizer when the fist leaves emerge in the spring. And then add some bone meal when the flowers open. Some years, I don’t fertilize at all and my daffodils are spectacular. 

3.  If you don’t believe it’s a shade issue or a fertilizer concern… dig up a few bulbs. If they are soft, dark brown at the basal area where the roots emerge from, and you find white/pink coloring when you peel back a few outer scales, you might be looking at F. oxysporum. This is a fungal disease, and this could be the cause of the non-blooming bulbs. If this is the case, I would destroy the bulbs. Do not replant daffodils or other bulbs in the same area. Remember, bulbs need to be planted in an area that receives adequate drainage and sunlight. Purchase new bulbs and plant them in another area of the garden free of fungal spores.

From Missouri Extension:

Daffodil, narcissus or jonquil?

“Much confusion has existed over the proper name for these plants. Actually, both daffodil and narcissus are correct. Narcissus is the generic botanical name given to these plants in 1753. In England, however, the plants commonly were known as daffodils. This term was carried to other countries by English-speaking people. Jonquil refers to a specific kind of narcissus, and is not correct for the group in general. True jonquils have a reed-like leaves and fragrant flowers. Narcissus, then, is the correct botanical name for the genus; daffodil is the correct common name for all members of the genus; and jonquil correctly refers to one particular division of the genus.”

https://extension.missouri.edu/publications/g6610

Treat both your "narcissus" and your "daffodil" the same.

I do hope this is helpful. Please reach out if you need additional assistance or have other questions.