The fringed water lily in the pond (Nymphoides peltata) has never been very robust in our pond, (I think it might not get quite enough sun, and the duckweed threatens to overwhelm it at times) but this year for the first time it's flowered.
I'm quite surprised about any Fringe lilly plant being 'not robust', usually they take over the pond, maybe it's a question of how much light & nutrients they get ?
In my (fish) pond I have to cut out literally piles of it (even more so this year), unfortunately removing some flowers in the process, bumblebees love it, quite strange to see bumbles flying & landing near the water surface
That's a lovely display of lily pads... I think you're right, mine just doesn't get enough light to grow that vigorously. Come Autumn, the pond is in full shade and won't get any sunlight falling directly on it again now until next April.