I'm just guessing that your yard is not a highly-acidic, boggy, swampy area. I'm growing them in my yard, too, and although they are perfectly happy as to blooming and spreading, I would be shocked if I ever got a berry.
There are all kinds of plants that bloom, and have lots of fertilization available, but don't fruit. Take tomatoes, for instance...nights can't be too cold, days can't be too warm. Some plants have to have the perfect amount of sun...not too much, not too little. So something in the natural habitat is what allows the nagoonberry to fruit, but whether it's the moisture, the high acidity of the ground, or something else, I don't know. This year, I transplanted mine from the nursery bed to under the roses and peonies. I'll be happy with them just blooming brightly in the spring, filling in until the other plants take over a few weeks later.

Yes, there is just allot we don't really know why. I one's had a
mushroom growing bug in me and grew allot of Oyster and Shiitake mushrooms. I found out that some other fancy mushrooms can not be cultivated because of other factors
which can not be mimicked, some of them only fruit when they grow within one or more species of trees, the root system of these trees makes it possible.

Do you only have 1 variety? Maybe you need a pollinator. Bingo.

I never heard of these, so had to look them up.
Description is very attractive to me...wonder if they would grow in Ontario.
Really like idea of fruit-bearing 'groundcover'. And pretty flowers too.

From what I found, they need pollinator, and acidic & bog-like ground to grow & fruit. A nursery in US was offering 3 different varieties.

Rina

Are these berries related to the Dewberry. ? They look so much alike on the pictures.